The most annoying bug for me is still there. About 50% of the time the log in screen wallpaper will revert back to the default 10.10 one which I dislike. I just started using a password just because of how much I like the lock screen and it's won't work right half the time.
Yep, best build for me so far too. First DP where Mail is working for me. Wifi speeds seem to be fixed on my RMBP, Safari is far more stable, and overall the system is faster/more stable. Sure there are still a bunch of annoyances, but its rdy to be used as a daily driver I'd say.