Personally, I'd rather keep the Spaces animation. I transition between 4 spaces (in a 2x2 arrangement) frequently throughout the day, and the transition animation is a great, minimally-obtrusive way of helping me keep my bearings. If I accidentally switch to the wrong space, I can usually tell before my eyes have a chance to recognize the contents of the windows, just by seeing what direction all the windows are moving in. That kind of perceptual awareness isn't merely eye-candy; it's actually useful!

Well, this doesn't disable the little spaces thing that pops up in front of the screen when you switch spaces. That still gives you a visual guide as to what space you are switching to.