Maybe it's just me but I don't get those "turn UAC off" comments you get every time with vista.
Every little security feature is just fine with me. But I'm sort of paranoid anyways, comes with my job description sorta.

I'm running P7 and P7pro on vista with uac on (obviously) without problems on desktop.
Haven't tried Pro but my P7 gave unexpected crashes on my Vista laptop. Most likely related to the nvidia 8600M-GT graphics chip. Never liked the small(er) resolution display much so I didn't put much effort in solving the problems.