Vista x64 works like a dream. Thanks to Microsoft's Certified for Vista program, 64-bit is going mainstream. So long as you have internet, Windows will find just about any driver.
Example, Linksys states that they do not have 64-bit Drivers for their PCI wireless-G adapater. I plugged in the ethernet cord, and Windows gave me generic Broadcom wireless drivers, after activating the card Windows did an update and found...Linksys Wireless-G PCI drivers. Pretty impressive I have to say.
Performance wise, I say it's kind of like commanding an army, the bigger the army the more generals/captains you need. Vista can manage resources much better, (and manage a lot more), and more efficently, but it needs more to be able to do so.
Also, being able to hit the Windows button and type 2-3 letters + Enter to open programs/files is extremely useful. I am quite spoiled, and when I work on Client's XP machines, I find I am no where near as quick to perform. And note, I was extremely used to XP.
The only thing I don't like in Vista as much is the networking setup, but I know that once I start to master them they are much more comfortable.
Oh, and Vista is almost uncrashable. I have never seen the system not be able to recover from even heavy errors. It is very good about being able to do everything seperately. If you want to hear why there is such bad press for Vista, go here: