There are two G7s now, the 10-day G7 and the 15-day G7. I’m using the 10-day and have pretty much since it came out. I’ve tried endo-samples of the 15-day (so they are samples and the best that Dexcom can provide) and have chosen not to go down that path.
For the 10-day after swapping from the G6 I found it so much better, so contrast with your experience. For me the much smaller footprint means I do not detach it half as often. I also find the transmitter reliability greater though, because every new sensor is a transmitter change, others have reported problems (e.g. with the Omnipod 5).
The accuracy was, initially, pretty much the same as the G6. It was nice having something that started up after half an hour, not two, but the results were completely bogus just as they were with the G6. It takes a Dexcom around 12 hours to soak in on my skin. The 10.5 day time, with the 12 hour overlap, was a real boon; I could (and do) run two sensors in parallel though that’s a lot of work in software terms.
Recently the accuracy has been AWOL. It’s not specific to the G7; it is Dexcom. They dropped their quality control and there was some kind of issue with the “sensor coating” apparently. I don’t know if it affected the G6 too; it took a while to filter through the supply chain and I think I’m probably living through the nightmare with my current batch of G7s.
I did ask my endo about going to the Libre because of the current unreliability (which is really bad) but he said he had found the Libre to be unreliable and wasn’t willing to swap me to it.
That’s when I got the G15 samples (two of them). They didn’t last 15 days; they both failed around the end of the 14th day. That might have been fine, depending on whether I could get a prescription for more than one every 15 days, but they consistently started to fail around day 12. By that I mean they gave the readings that are symptomatic of a “sensor error” for me but, ho hum, there was no report of a sensor error until around day 13 at which point I got, at at least one time, one reading every 15 minutes.
I’d go for the 14-day Libre; the one which gives readings by bluetooth every minute. This is because it’s no longer a case of, “If it aint broke dont fix it.” for me; Dexcom is broke. G15s don’t work and G10s don’t either.
If you have to do Dexcom because you have shares then go for the G15; the ones I had were accurate after the first 24 hours and did last for 11 days beyond that. This is Dexcom’s leading product so, I guess, the only one they really care about.