670G or wait for 780g (currently on TSlimX2)

Thanks so much Dennis.

Overall have you been happy with Dexcom and T slim?

I’ve seriously watched so many YouTube videos and read so many posts online about T slim vs Medtronic. My overall take is that people are happier with Tandem and Dexcom than the 670g.

I am happy with my control on the 670 overall and the auto mode has been so great for night time control but… it’s so needy, alarms often, requires MORE fingersticks and often the CGM is not super accurate for me. And my Medtronic sensors last an average of 4 days. Although Medtronic will replace them I am spending endless hours on the phone with them which is just annoying.

Ultimately I guess I won’t know til I try it but I’m trying to make an educated decision. I am also pumped (no pun intended) about tandems upgradeable software and am excited for them to release their closed loop system.

Any personal experience you can share on Tandem/dexcom is appreciated.


1 Like

Brie, so far I am very happy with both my CGM and my pump, although I have not been able to use all the features. So far the major drawback is that the t-Slim x2 pump shipped to me in January was the “latest & greatest” stuff fully installed - being the latest software, which can not be reset to an earlier version, the pump will not connect with my G5 transmitter - it only will work with the G6.

Almost all my G5 sensors [all but one] have lasted and given what appear to be accurate readings for the full seven days; a couple of times because of delayed delivery I had to restart the sensors and got an additional week of readings. One other sensor I messed up on insertion, skipped the step of withdrawing the insertion needle and I had to replace it after a day or two - that is what caused me to use my last sensor for an additional week.

Although my pump does not work automatically on “Basal IQ”, I manually implement those features to mitigate hypoglycemic events by either reducing basal flow rate or by suspending my pump. My only ‘problem’ so far is when I lower the basal rate during the night, I have the reduced rate run too long and some mornings I’m higher than I want to be.

I’m looking forward to to “Control-IQ” which should be available in November; and by November Dexcom promises to be past their “supply issues” [my opinion, too many in-stock G5 transmitters & sensors labeled Medicare] and I should be getting my G6. I tried to get into the Control-IQ final testing program, even spoke with the deputy director of the program, but I was considered too old and too long with diabetes. I also didn’t live near the University of Virginia where the algorithm was developed and the testing conducted.


In case you haven’t seen it yet, I bring you good news. Medtronic now has a link for replacing sensors online:


Is that site for requesting replacements for faulty sensors or for ordering supplies at cost?

While I’m here, I’ll go ahead and add in a little more about the 670G vs. TSlim debate. I’ve posted my fair share of complaints about 670G. I’m fairly new. I’ve been using it with Guardian link system for a few months. I’d never pumped before. Anyway, despite my ordeal, I got my first A1C, since beginning pump therapy and this week and it was 6.8. My last one was 8.0 in March of this year. The 8.0 is what caused me to go with pump. So, I have some thinking to do and to decide how long I will deal with the 670G. I can’t argue with success, but, I do hope to either get better with handling the multiple daily disruptions it causes me or to transition to something else. I wish Medtronic would work out the kinks, because, I don’t want to switch. But, for now…I’ll stay put as long as numbers are good. My Endo is happy, but, I now think that the only thing holding me back is the 670G. lol It’s funny, because, it’s helping me and holding me back at the same time. lol If it will allow me, I see no reason that I can’t achieve a 5.9 with more practice. (My best prior A1C was a 6.7, but, that was filled with lows that my Endo was not happy with. Other numbers included 6.8, 7.0, 7.2, etc.)

Thank you! I knew that and I’ve already reached my max I am replace online… doh!

I’ve had a similar experience.

I’ve usually had A1c around 6.8. Was down to 6.4 but with WAY too many lows so we purposely tried to get rid of lows and shot up to 7.7, then 6.9, then 7.1. My last A1c while on 670g was 6.6, with way less lows, so overall better control.

But… I was pumping for many years without a CGM because past Medtronic CGMs were terrible so I’m not sure if it’s the closed loop or the CGM that’s giving me better control.

I started the closed loop one week after starting the CGM.

I’m pursuing T slim/dexcom G6. Worse case I’m out $1000, hate T slim and/or Dexcom and go back to the 670g at my next refill in 3 months… I’ve literally spent hours and hours and hours debating, which on its own probably says something about my exacerbation with the 670g.

I’ll keep you posted.

1 Like

@briew, please do post what happens. I’m so very curious, because, I really want to know. ALSO, have you tried 670G without Auto mode? It’s my understanding that it’s much easier to live with and to get better numbers (I have higher numbers than I should. Like why not 80-110, as opposed to 125-140?), if you run in manual mode. My 7 day summary under History is saying that I’m in Auto mode 98% of the time!!! It used to say 98%, but, I pre-soaked my last sensor and it warmed up in only one hour!! That was a nice tip from someone and saved me an hour. Sooooooo, should I try going out of auto mode to see if that is more feasible for me???

I will definitely keep you posted. I’m VERY nervous about switching. Maybe partly because change is hard… I haven’t really used the 670 without Automode except for short times. I actually really LOVE the automode, which is one of the reasons I’m nervous to leave Medtronic…but… I love it in the way you love Kale, or running a 10K… I love it/hate it! I love that my nighttime sugar is well controlled and I’m having way less lows. Before automode I was seriously scared to go to bed with my BG less than 150 or even 180 because I was afraid I’d crash (because I often would), then wake up with a RAGING headache after going low in the middle of the night or… I’d wake up at 250 fasting which also sucks. Now I wake up 80-110 and no headaches. AWESOME! And my endocrinologist makes good point saying that if you sleep a 1/3 of the day, even have good control a 1/3 of the day, every day, makes a HUGE difference in your long term management… (ugh, now I’m talking myself out of T Slim again…) See, I’ve literally gone round and round… But again, not sure if this is Automode or CGM that makes the biggest difference, as i assume I’d alarm if I was going low in manual mode or with Control-IQ in Tandem. A few nights ago I had chips and salsa, then ate quesadillas and my BG was like 300, plus I had a bad site, which I changed… so I spent the ENTIRE night with the 670g alarming every. single. hour. telling me my BG was high, kicking out of automode, asking for calibrations, you name it. All. night. long… then it drives me crazy when it alarms to say: your BG is high but 1/2 the time it won’t let me correct. I even did an injection just to cover myself. I did wake up at like 98 but literally all night of alarms. and had to work 12 hour shift the next day. So… yes, not really the pumps fault for what I ate, and its actually doing its job, but I still think there is room for improvement… And… all that said… Tamdem is supposed to have a closed loop being released soon that auto bolus/corrects for highs which i think is amazing. And I have to keep telling myself that the ability to do software upgrades on Tandem over the next few years will be a better long term solution (I think) than being stuck with the 670g where it is currently at for the next 3 years until my warranty expires and I can get something else. I’ll keep you posted!

1 Like

Hi everyone. I’ve decided to go back to my TSlim X2. It pains me to do it because I was a LONG time Medtronic customer. And, like the above thread mentions, I did the Dexcom/Medtronic 530g thing because I could not stand the Medtronic sensor. It was painful, highly inaccurate, and a nuisance until more recently. I finally decided it was dumb to use two devices that did not communicate, and I was not getting optimal control using the combo. So, I switched to the TSlim in January because it communicated to the godsend Dexcom. The slim was OK to me (I think I was being stubborn since I was partial to Medtronic) The charging the pump thing really was difficult for me to remember to do. The Medtronic 530g ran on a battery so that was much more convenient than remembering to charge yet another device. In July, I decided to go on the 670G after reading about the latest sensor accuracy. Yes it was accurate, but I quickly realized how spoiled and how easy it was to ‘set and forget’ the dexcom sensor for 10 days. No calibrations and NO adhesion problems ever with the dexcom. That puppy stays on the full 10 days with Barrier wipes. No extra overlay tapes. During the brief couple of weeks on the 670g both manual and auto, I wasted through 3 sensors before their time was up due to sensor errors. And 1 time an adhesion issue. So after contemplating, the reasons I went back to TSlim X2: 1) The sensor is set and forget for 10 days no calibrations, 2) the basal is awesome and I wake up with normal blood sugars. I will say with 670 the manual mode was just as good regarding suspend before low, but the automode was bad with this, it’s like the suspend feature for automode was delayed hence I resulted in lows. 3) the TSlim is much lighter now that I have been wearing the 670 for a while. TSlim is slim and smaller, fitting nicely into my pockets. 4) I like seeing the graph on the home screen, the 670 automode that goes away 5) I like the phone and watch connection with dexcom. That was really hard to get used to not having that with the 670. So I hope this is helpful to some that are contemplating what to do. : )

1 Like

Thanks! It actually helps confirm my decision to switch to T slim! I’ve been trying to find someone who’s tried both and now YOU have! You were the first person I’ve heard of that switched FROM T slim TO 670g. most things I read/watch have been people complaining about the 670g… so… its interesting to me that you have now gone back to T slim. I hope you find a system to charge, i"m like you, I am nervous about that, as my devices are always dying because I don’t charge them! And… I worry I’ll be out hiking or something and have forgotten to charge and it dies, whereas now I just carry and extra AA with me in my test case. Thanks so much for the update. :slightly_smiling_face:

@briew, OMG, your description sounds JUST LIKE ME! Unreal…I get it. THIS is most of my problem. Also, I can’t trust the sensor. It will leave me at important times. That happened before McCartney concert. My friends are socializing, having drinks, laughing, while I’m in the bathroom changing into my THIRD sensor for the day! (Which fails half way through the concert and leaves me with no CGM for the rest of the night, so that I have to set alarm and check BG every hour to prevent low, since, I’m no longer in Auto mode and with no BG no suspend before low. Good for me, I did it, cause, I had to treat a 49!)

I’ll be anxious to see what you think. How much will it cost, if you don’t mind saying.

@RosiesAllStars, this is really helpful. I’m new to 670G and trying to figure out what to do. I feel like if I can manage 670G, I can handle just about anything. I’m shy of the TSlim, because, I feel so burned with Medtronic. Just want to be sure, before I change. Plus, there’s the money thing. AND, I’ll have to return to see my CDE again for the transition. So, it’ll be a big investment in time and money…AGAIN. OH, I did use Dexcom G5 for a couple of years, before I got pump. I actually wore them both at same time and they were pretty close most all the time with my meter.

Also, did you see any benefit in staying out of Auto mode with the 670G?

@HighHopes I’ll let you know what the final number is… Tandem’s loaner program is $999 and you can use their pump til the end of your current pump warranty, which for me is a pretty good deal because I’m only 1 year 2 months into my 670g warranty. (I had a 530g previously.) Then… because the medtronic CGM transmitter has a 1 year warranty, I have to pay out of pocket for the Dexcom Transmitters until that time comes (December 2019)… but my insurance doesn’t care who I get sensors or tubing from… so with my insurance that will be covered at 100% regardless if I get them from Medtronic or Dexcom. Costco (if you have where you live) has a deal where you can buy the Dexcom G6 transmitter out of pocket for $279 for 2 transmitters (they last 3 months each- so 6 months worth). All in, not cheap but I figure this is something i have to deal with every single day and if I can make it work better for me… in the long run its worth it and $1300 is probably less of an investment than buying a cup of starbucks every day for a year! (why do we always use cups of coffee at Starbucks as cost references??.. seems like a thing!) I also recognize I have the resources to make this switch and many don’t. Anyways, I’ve spent a lot of time trying to figure this out so any questions I can answer, I’m happy to try. Lastly, I heard Tandem is only offering the $999 thing until the end of September, but who knows if they’ll extend it.

1 Like

The benefit for me of not being in automode is first, I really like seeing the graph on the home screen. Automode has the shield and to me, I prefer to see the graph that depicts where that number came from and where’s it is going. Second, I noticed that because automode bases corrections off of 150, I either seemed to run higher for longer, or I would go low because the suspend seemed not as accurate as with manual “suspend on low” feature. Also, the times the sensor failed or “sensor unavailable” due to fixing an unspecified issue could last upwards of 3 hours. Manual mode works like Basal IQ on TSlim. Manual mode on 670 is good. Maybe I just didn’t give automode enough time, but time is of the essence these days and we all want good sugars yesterday : )
Good luck with whichever path you take. I just wish Dexcom would marry Medtronic and non of this would be an issue. I actually can’t believe automode got fda approval with how many problems with the sensors they seem to have (fail rate, coming off easily). And I’m surprised the Control IQ with TSlim was pushed back a few months. I’m excited for that software upgrade because I know how easily and accurate the Dexcom G6 is and how the basal IQ is awesome. Crossing fingers Control IQ delivers with more reliability than the Automode.

1 Like

Thank you for all the information I’ve gained from this site. You are truly knowledgeable people who have walked the walk rather than just talking about things academically or trying to make a sale.
I’ve been on Medtronic insulin pumps since 2011. Even though there are issues, the advantages definitely outweigh the disadvantages when comparing to just using shots for me. As a type one for 50+ years, I have learned to find my own balance. Currently my A1c is 6,0 and having fewer highs and lows, although they still happen.
I’m currently on the Medtronic Paradigm 551. Since it’s out of warranty since last month, Medtronic has gotten my insurance approval for the 670g. Maybe I am a creature of habit, yet I am hesitant to place the order. My doctor thinks the new system will be better for me. I still don’t think I can use a CGM since it stressed me out so much last year. I know there’s a program Medtronic has where are you pay $100 that entitles you to get the next model for $100 when it’s available. My gut is telling me to not to replace the 551 since it seems to do the job, and I don’t think there would be too many advantages to getting the 670g now.
I’d appreciate any thoughts you may have on this issue, realizing that everyone’s situation may be different than mine.
Thank you.

Hi Jayne,
I was in your position 4 months ago. My Paradigm 530-G was over a year out of warranty and I was struggling with what to upgrade to after being with Medtronic pumps since 2001. I too am a creature of habit so I decided to upgrade to Medtronic 670G with Guardian 3 sensor. The new pump is very different
It requires a lot of interaction that I’m still adjusting to , Auto Mode with the sensor was way more hassle than I cared to deal with. The Medtronic Tech support team was great when I was struggling with the sensor issues but after it all I eventually discontinued the sensor. I’m currently on Manual Mode and doing just fine.
Good luck,

Thank you so much Jodi. My gut is telling me to wait until my pump goes bad or wait until the 780g is available. Hopefully the pump I have will last until the next model is available. Hopefully the 780g will be a significant improvement to the 670g. I will just have to wait and see what path to take since it doesn’t seem like the 670g will be an improvement for me.
Thank you again.

My Medtronic Paradigm warranty expires in November. I have used all Medtronic pumps since my first in 1993. I’ve never really considered a pump other than a Minimed Medtronic. I’ve been using the Dexcom CGM which I love, especially since I calibrate only 2x per day. Am I understanding that with the 670g more calibrations are required. Many years ago I tried the Medtronic CGM. It felt like a harpoon being inserted and could not deal with the pain. Has this really improved. I am also concerned about how well it adheres. Does being in manual mode vs. auto cause the closed loop to suspend. Maybe I should go to another pump but out of 38 years with T1D I have used Medtronic for 28 years.

You have to calibrate every 12 hours or it stops reading until you do. Medtronic recommends calibrating every 8 hours. Automode is closed loop, but manual mode is like a normal insulin pump without closed loop, though it does have “suspend before low” and “suspend on low” in manual.
Automode may require extra BG readings to be given. If your sensor reading doesn’t seem right for the amount of basal insulin it has given you, it will ask for a BG reading to be safe. You can’t hide correction boluses or small carb meals from Automode, you have to input all that information or it will think it’s calculations are going off the rails.
The sensor adherence is ok, I have never had an inaccuracy in my sensor readings and my sensors usually last 6-7 days. The entire month of July I didn’t get a sensor to last more than 3 or 4 days however. I live in Texas, and I’m a forklift mechanic, so I’m usually sweating in the corner of some customer’s warehouse. My cloths will be 100% soaked by a few hours into the day. Now that temperatures have dropped into the mid to high 90°s in September, my sensors have all lasted 7 days though.

Edward @SpecialEDy, that may be the most progressive advice yet posted for those for whom Medtronic Automode appears NOT to work for them. So many people go too quickly into what they assume is “diabetes plug-n-play” and don’t take into consideration that there isn’t a meter implanted in the gullet to measure meals and the sneaked snacks.

Thank you for posting so many of your very astute observations.

1 Like