Yeah, i've tried it out myself and performance wise i'm very impressed. Windows itself seems a lot smoother and even small apps like the picture viewer seem faster too, i've done a few benchmarks too and even 32 bit apps get a performance increase, which is great to see.
The only bad thing about it is driver support, there was 2 pieces of hardware I have which aint got drivers, my modem (but thompson are working on drivers) and my eyetoy (yes, it can be used on the pc with hacked drivers)
I'm staying dual boot for the moment until drivers are released for my modem, then when they are i'm going to stay x64