I've setup my PC to dual boot XP and Vista and can access the same installation of TRS2006 from either OS, and for me Vista runs better than XP.
Vista generally tends to handle files better than XP, so TRS caches and runs a little more smoothly. I definately notice a difference when dealing with large numbers of dependencies in CMP!
I also used to have the dreaded 'choppy' sound issues under XP. I tried everything to fix it - different drivers, hardware acceleration settings, disabling on-board sound and using a soundcard instead - nothing worked. Under Vista though, sounds works the way it should straight out of the box.
Overall, I'm completely happy with the way TRS runs under Vista.
Cheers - Brian