Yeah, I'm using the pre-beta of SP2 for Vista. It does seem to have a performance increase but for some reason boot takes SOOOO long! I'm at the boot screen for like a minute and a half, then I'm at a black screen for 30 seconds, then it goes to the login screen, then it takes maybe 30 seconds to go to my desktop for it to start loading...but when it's all done it's all nice and fast.