I got x64 7100 installed Saturday morning and had just enough time to install the Steam Client, have it download all my games and get Virtualbox up and running with all my VM's. I haven't had any time to mess with it beyond that though. Blame my wife for giving me a social life.
I won't have any time to play with it tonight either, but Wed I should have all evening to mess around. So far it looks good though. This weekend I'll have time to put it on my laptop as well and get everything loaded on that.
So far I'm very happy with it. I went clean install (always with a beta) and everything is working great. It's faster than 7057 and haven't run into a single bug (but again, haven't had much time with it yet).
I've already converted 3 people at work over to Win 7.