I'm running Vista 64, and there are some learning experiences. My 64 bit stuff runs like a dream (Solidworks, 3DS Max).

I've had pretty good luck with 32-bit applications, but if you've been running any 16 bit stuff, you're out of luck. I have to keep my WinXP system up to run AutoCAD 13 (my version of stone knives and bearskins).

Even 32 bit programs get twitchy if they're too old. Photoshop CS runs, but has problems. Acrobat 7, too. I could fix a lot of this by updating to new editions, but I can't afford it right now.

I'm still running 32 bit IE 8 because some of the plugins, like Flashplayer, don't have 64 bit versions yet.