The only problem I've experienced with the x64 version so far is that the media player was skipping - apparently due to the auto-defragmenting program hogging the hard drive. At least, every time I experienced skips, the auto-defragger was running and the hard drive was going nuts. (I'm assuming this issue probably isn't limited to the x64 version.) The GUI is nice, but in the end, I'm not really all that impressed with Vista. Even in XP I prefer the classic GUI. IMO, all Vista is is resource-hogging eye-candy. (700MB+ of RAM used with nothing but the OS running seems a little excessive to me.) If only Microsoft had plans to release DirectX 10 for XP...