I've been using GOS on a 10a for over a week and it's mostly fine. For daily use like phone calls, messages, emails etc; no problem at all. I've only encountered a couple of issues, 1) unlocking the screen requires swiping all the way across the screen so you can't just flick it up with your thumb 2) app update notifications are sometimes unresponsive. I don't know if these things are due to GOS but if they are, I'm sure they will all be ironed out. It's good enough for most use cases as is. When I get around to it, I'll check if the issues I've encountered are known bugs and if not, I'll report them if needed.