WOW!!!!! Huge FPS increase, very smooth,.. running an evaluation copy installed FSX with Acceleration.. getting 100% in FPS,,, on ground with sliders maxed except autogen at Dense and Water at 2x... getting about 37 fps on ground.. running E6600, 4 gig with Nvidia 8800 GTS with 512, I think I will stick with it... added Windows 7 as dual boot on my rig, think I will uninstall XP 64bit Pro,,, beats the heck out of it,, also all Vista drivers working great......

Sounds very impressive. The only thing I'd question is whether part of the performance improvement is due to a 'clean build' of the OS. Maybe your XP Pro 64 has become cluttered and is running lots of services etc.?