@hellwig
That's why I said that x64 MIGHT have had something to do with it, but I'm guessing not much since pretty much all my apps are still 32-bit. And btw, I previously had 2GB of RAM under Vista, and upgraded to 4GB (yes, I know it can only address 3GB in 32-bit; I was preparing for x64) because Guild Wars appears to have a bit of a memory leak that flooded my machine into virtual memory after a couple hours of gameplay. It did give me a noticeable speed boost, but it was still sluggish overall. Windows 7 is just way faster, no matter which way you look at it. I also have 7 32-bit on an old Dell Latitude D600 with a Pentium M 1.6GHz CPU and 768MB of RAM. Aside from lacking Aero capability, it runs very well (I dare say even a little better than XP)! I once tried putting Vista on that exact same model of laptop, and it was what I would consider barely usable.
As for running it on my main machine, I held off putting the beta on it, but the post-beta builds have proven to run very smoothly on my test boxes, and since I had a spare partition on a secondary hard drive (which was actually my old XP installation before switching to Vista), I had nothing to lose by setting up a dual-boot. All I have to do to get rid of it is reset my boot loader and delete the Windows 7 partition. My test boxes are a bit on the weak side, so I wanted to see how it would do on a true custom-built performance PC. Having used it several days now, I'm guessing I'll be running this build until the RTM comes out (maybe even until the RC time-bombs out), and I bet I won't ever have any need or desire to reboot into my Vista partition.