So far all the AT, Mtronic and even the 500i I've owned have had hiccups, and know many other that have. The 462 and 572 very minor, just goofy idle a time, otherwise those two have been perfect, likely just the change in weather, these things don't like a drastic change in weather, a constant in southern Ohio.
The first few generations were garbage IMHO, both brands. The 500i is in the shop right now, didn't want to stay running, now it floods itself bad. I wasn't going to say anything until the issue was resolved, but it's been with the dealer, and now with Stihl for two months, lots of head scratching. But yeah no biggie I just pick up one of my older trusty saws and not worry about it, If I depended on a saw, not sure I would trust any of them just yet. If I had to choose definitely the 572 or 462.
I believe this is what's going on with my 500i.