I find that when I used the latest nightly build animations don't seem to work very well. Some only go through their loop once or twice, and others don't even animate at all. This is very annoying as I get animations from people and I cannot see them. Besides that, Webkit runs very smoothly, and faster than my version of Safari.
Can you give an example?
You don't specify what kind of animations you're talking about, but CSS animations have had a lot of work. Re-open if you can provide a testcase that fails in a recent nightly build.