Very good. 
I'm building an SLI rig...the SLI part always lags behind, though..
..that will have 3GB of fast, performance memory. What you said makes me want to give it a try. But the part about the drivers needs to be solved, quickly.

I'm building an SLI rig...the SLI part always lags behind, though..

I have beta tested Vista since the Beta 2 release. (thus, been using it for over a year)
Most of the issues are driver and software compatability issues. DirectX 10 (Vista) has once again moved 3d modelling technology far ahead of consoles such as PS3 and Xbox360.
The security features are well above most if not all LINUX platforms.
In short, it is a sweet, elegant OS that requires more RAM than you probably ever thought you would need to run an OS.
Trust your resident engineer: It is the best product Microsoft has ever offered, but TODAY ... might be for everone.