Please get your facts straight. Vista will be faster than XP with a decent rig, you'll only notice a decrease in 3d performance. Believe it or not Vista can perform many functions faster than the same system running XP. Needing a machine capable of running Vista is a moot point and shouldn't be considered at all.
Well, that's kind of my point - I define performance as performance in games, and in games, Vista lacks(yes, I meant lacks). By the way, I have more than enough for Vista, and it's as much the incompatibility with stuff that turns me off it as it's Microsoft's way of being a bitch about us having to change to it.