Honestly...bad. I haven't had one issue with my watch, and I've had it since launch day. However, I've had 2.0.1 on my watch for about 10 hours and in 6 hours the battery completely died, a lot of 3rd party apps won't launch and now it isn't tracking any of my fitness data at all!
You poor bastard!
I had an issue where some apps didn't have their icons. Was just a cross hair type image, since 2.0.1 this issue has been resolved.
Agree with the other comments, everything seems to be much faster.