Vista vs XP for SH4 1.3

[DimDoms]

Forgive me if this has already been discussed...

Is there a consensus on the quality differences between Vista and XP for SH4?

I ask because I'm seeing terrible performance in Vista, with all effects off, with standard and latest beta drivers, and before I go through the hassle of reinstalling XP etc., I wanted to make sure that I would be able to expect proper performance of SH4 on XP.

I have a decent box, 7800 GTX, X-fi etc., 2 GB RAM, so I don't understand why I'm seeing so many problems. Any ideas, comments feedback? Anybody downgraded from Vista to XP for SH4 and seen great improvements?

Otherwise I'll be shelving SH4, much to my chagrin.

Thanks in advance,

Dimdms.