Yeah, I know, I'm a Linux geek, and as far as I am concerned Microsoft ranks up there with that person who bought/stole/connived his way into winning the last election in evilness, but I had to try the beta, if only because it was a new toy to play with and it was free.
Granted, I never tried Vista, cause I'm a cheap bastage and won't give up the benjamins, so I can't say for sure, but this version seems to perform better than the anecdotes say Vista does. Only issues thus far is the occasional blanking of the screen, like the graphic driver is refreshing itself, and it seems to not like DVD movies.
The eye candy is OK, but nothing I'm not used to. Beryl/Compiz has been doing that for a while on Linux.
It's usable, but I don't think I'd spend money on it.