vista is fine now. it just sucked the first year it was out.
you still notice some slowness with video stuff like remote desktop and such.... but for the most part win7 isnt that much faster at all. i use vista on my servers, and any pc that i use daily i like to have win7 on there. win7 has a lot of little nice quirks that make everyday computing easier.
all that said, both are lightyears better then xp with sp3. i had to go back to xp on one of my boxes, and quite frankly, it sucks.