My experience has been very different. I used Medtronic Guardian 3 sensors for 2 years before switching to Dexcom. For me, the Medtronic sensors were a pain. They never did warmup right. It always took 12 hours and multiple calibrations before they got on track. At least 10% of the time it wouldn’t get on track and I’d have to pull the sensor, call in to get a replacement, and start the process over the next day. Calling in, the people were always nice, but the phone maze to get to them was tedious until I finally complained and got a direct extension. (Pretty sure their call center is outsourced to Indonesia or something, too. I can’t quite place the accent, but they’re clearly reading off standard scripts.) Finally, Medtronic implemented a website that allows you to fill in the sensor replacement info yourself, although you can only use it 3 times a month, so I had to call in whenever I needed a replacement more often than that.
Once the Medtronic sensor gets on track, it still needs to be calibrated 3 times a day, and the pump is programmed to ask for a finger stick BG value whenever you want to do a correction bolus. Their sensors last 7 days, although mine usually got wobbly on the last day. So I basically got 5 good days out of a sensor.
Dexcom has been a breath of fresh air for me. It doesn’t need calibration at all. Insert sensor, wait a couple of hours, and it’s ready to go. I do still calibrate daily, just to be sure. A couple of times it’s been a little off on the first day, but a calibration or two usually gets that fixed. Twice I had trouble where it was way off on the first day, but leaving it overnight gave it time to sort itself out and it worked great after that. I always get at least 8 good days out of a Dexcom, and it’s not uncommon for it to go the full 10 without a problem.
When I wanted to call in to Dexcom, they had a live chat option on their website, which was much easier than a phone call for me. But, like I said, it turns out if you’re using a Tandem pump you have to call Tandem for most sensor issues. Getting through to Tandem is easier and faster than getting through to Medtronic customer support, and they need less information from me, too.
In short, the sensors I had trouble with lasted longer than a Medtronic sensor ever would, were more accurate during that whole period, needed much less maintenance/calibration, and were easier to replace. No CGM is perfect, but my doc said she wanted me to switch because “Dexcom is the gold standard CGM,” and I’m glad I listened to her.