If Vista tanks your benchmarks, then explain to me why the top 9 scores on 3DMark06 on the ORB were achieved using Vista?
I had a huge debate about Vista a while back on another forum. The question was whether you could run a simple home audio studio on Vista, and what others were using. The thread went on to reach 70 replies or so, none of which answered the OP's question. Everybody promptly responded by saying how much they thought (or had heard) Vista sucked. Did any of them have experience with it? Of course not, that'd be too rational.
As a side note, my dad recently switched from XP Pro to Vista Home Basic (not even premium or business), because he didn't want to put up with the two days worth of updating we would have had to do by reinstalling XP. He also didn't need the network management stuff as he doesn't log onto domains, but he wanted an OS that didn't have major loopholes in security. He has popped in his XP hard drive from time to time (he had got a new hard drive which was the big prompt for the switch), but only because he had forgotten to solve a few licensing issues for some software he was using in a program. It hasn't crashed yet, and it runs just as fast for him as XP.