Just throwing in my 2 cents regarding the upgrade from Win7 to Win8:
I can confirm it does indeed run faster/smoother on the same system. Whereas I used to hibernate instead of completely shutting down in Win7, I don't bother anymore because it's just as fast to boot clean. My audio tools (FLStudio and Audition) and associated VSTs run without issue. I was able to lower my latency a bit, and the random crackling I had on my FA-101 is gone in Win8.
If someone refuses to use Win8 just
because of Metro, they're missing out. Yes, it's different, but it's a solid OS.
Expecting old games to run on it? Well ok, obviously it's not perfect.
For those of us who play more modern games, they run without issue for me.
Regarding the 8.2 update, I'm really curious to see how far they go to bring that the original start menu. I'd be very surprised to see it operate exactly as Win7.