Yet another 8800 on Vista user, and I can confirm that despite tweaking the hell out of my config settings, dialing down my resolution, fiddling with HDR, and updating every damn driver I can think of, this game is still S L O O O W W W W...
I can fully understand an initial lack of support for Vista - but speaking as someone who works for another small game dev shop, I can tell you that Microsoft (and Nvidia for that matter) has worked very closely with any interested game devs on getting their bits up to par for Vista. It is a shame that BI hasn't placed more of an effort here. With XP evaporating from the retail and volume sales channel, I would think that it is in BI's best interest to capture the Vista audience.