Since it's the same speed on my Mac Pro with 4GBs of RAM and my 1.2ghz ibook, I don't think that's the problem. Realistically I don't need to see the animation of the spaces sliding across the screen. It's not annoying when occasionally switching, but sometimes I'm trying to reference something on one space and working in another. Watching the animation over and over gets a little old. I'd turn it off if I could.