I have been running Vista 64 since it came out. Found more drivers for it then XP 64 which i had for a few months, maybe i didn't look hard enough.
Has been great, stable, runs everything i have. I've enjoyed it.
Been using Vista since it's rc/beta stage and haven't really had any major probs with it. No driver/app probs except for Acrobat 7.
The only thing that annoys me that Vista (and soon to be Win7) leaves little free space on my 36gb raptor drive (OS drive). Where with XP, up to 30gb of free space is available (after installing Office) - Vista only leaves up to 12gb free.
I am completely satisfied with Vista Premium x64 now even though it was a rocky road at the beginning. I only have 2 gigs of ram but I have yet to run into a problem related to this fact. I play games such as Far Cry 2, Call of duty (all of them), Bioshock etc... and use Photoshop and Paintshop pro with no lack of speed, kinda makes me wonder what sort of performance boost I would get by doubling or quadrupling my ram !!! I have not seen a BSOD since SP1 installed. I also have Vista installed on my Toshiba Satellite notebook with only 2 gigs of ram and no problems. I am a happy camper.