Since you are probably stuck with the Tandem for a while, you’d best learn how to make living with it easier for you.
I moved from a Medtronic 670g to the Tandem a few months ago. On the whole, I find the Tandem a big improvement, though there are some things I liked better about the Medtronic.
Filling Tandem cartridges is more difficult and time consuming than filling Medtronic reservoirs. There is no getting around that, though filling the Tandem cartridges does get easier the more practice you get.
The infusion set should not make any difference. I understand that the Medtronic and Tandem infusion sets are made by the same company. Neither should be better or worse than the other in terms of causing skin irritation.
As far as the Dexcom being out of range, the signal goes from the Dexcom transmitter to the Tandem pump, NOT to the infusion site. The Tandem pump is made out of metal, which shields the signal. You have to wear the pump with the front facing away from your skin because the front is the area of the pump through which signals travel in and out of the pump. (Which way the Medtronic pumps face is irrelevant since they are made of plastic, not metal.)
The messages from the Tandem pump can be annoying, especially when your blood sugar is tending high or low, but I find them far less intrusive than the Medtronic messages. In particular, the Sensor Updating messages drove me to distraction. I don’t know what idiot thought it necessary to warn every half hour not to do anything. At home, it wasn’t bad because I could turn off the warning each time. But when I was driving in traffic and couldn’t turn off the alarm, I wanted to rip off the $^&^* thing and throw it out the window. The HUGE plus of the Tandem, and the main reason I am happy that I was able to switch, is that the Dexcom CGM sensor seems to be far more reliable than the Medtronic sensors. Not only are the Dexcoms more accurate, they also last the full 10 days, whereas about 1/3 of the Medtronic sensors quit on me before the 7 day nominal life was up.
The other thing I didn’t like about the Tandem was that recharging the internal battery takes longer than just swapping the AA battery on the Medtronic. (I used rechargeable batteries on the Medtronic, and just swapped them, recharging the discharged battery each time so that it was ready the next time I needed it.) However, I got a battery bank that I could use if necessary. Most of the time, I use charging cords I keep in the car and around the house, so that I can recharge while driving, while using the computer, while showering, etc. That has made the recharging process less of a pain.
The biggest advantage of the Tandem pump though is that it lets me give correction boluses without doing a finger stick. It’s not that the finger sticks were a big deal, it is that I had to have my glucometer, lancets and test strips handy. Now, I can check my glucose and give a correction bolus quickly, e.g., when I am stopped at a red light.
As far as the touch screen goes, I too prefer buttons. On the other hand, I find the touch screen on the Tandem works better than the one on my Samsung phone.
So, since you are stuck with the Tandem for a while, make the best of it by making it as easy to live with as possible. I suspect that when you are able to switch your Tandem X2 pump for another pump, you’ll find you hate the new one. It’s always tough getting over the learning curve of new devices. And remember, ANY pump is better than injecting several times a day and having to carry all the paraphanalia with you.