I’ve had mine for about a month and a half. Not a ton of miles, but I should start logging a lot of miles soon. Zero issues so far. Initially the groupset only worked when plugged in. I knew what it was right away, the 1st set of batteries I ordered were a hair too short and were not making a proper connection. Ordered a different set that had a taller “nub”. That is not the groupsets fault, it’s a common issue when using these types of rechargeable batteries.
I might order another set, but would like it in carbon. Although the price will be higher than the $350-$375 you can get the current groupset for.
Here are the ones that worked well, surprisingly they were the cheapest ones too
Svenirven 14500 Battery, 2 Pack...
https://www.amazon.com/dp/B0BVWF93HG?ref=ppx_pop_mob_ap_share