I just finished putting together a new machine last night. Dual core 3.16GHz E8500, 4 gigs of ram, and a Geforce 9600 512meg vid card.
I finally decided to give Vista a try on this new rig. I wanted to see how the 64 bit version worked. I opened up a OEM copy I got from MS and noticed that the sticker on it said 32 bit only. So I looked at the other copy I had (Service Desk Upgrade) that clearly said 32 bit and 64 bit on the front cover. Great. Except that there actually isn't a 64 bit disc in there, and if you do happen to want what is advertised on the front of the box, you need to give MS your product key and order the disc from them for a few bucks. WTF.
Anyway, setup went smoothly and didn't take very long. Hit a big snag when Vista was up and running: I couldn't find a 64 bit driver for my wireless lan card, which made any updates impossible. Some Googling solved that, and once the machine was hooked up to my network, I was really impressed with how slick the OS is about handling drivers and any system problems.
I tried Mame on it, and to my surprise MK4 still has some slowdown in spots. Any other intense 3d games seemed to need CHDs, so that was the only one I tested.
Then I moved on the pcsx2 and tried out some ps2 games. I'm *very* impressed with how solid that emu is. I played Hokuto No Ken and Fire Pro Returns at full speed with virtually no glitches and perfect audio. Smackdown:HCTP also played close to full speed, but at times would seem to slow down a little bit. It surprised me that even the 3D Smackdown seemed to run almost perfectly. I thought ps2 emulation was much buggier...
Is Dreamcast emulation worth checking out?