Started cleaning up the rotoscope; first I lengthened and slowed down the shot, which massively improved things. I think it's looking a bit better now; the main things I had to alter were, as said previously, the speed of the ball's drops and the hangtime at the peak of the bounce. I messed around with the rotation slightly as it's falling, and also reduced the distance that the ball rolls away.
I'm not terribly happy with the rolling at the end - it looks off to me, but I can't seem to put my finger on exactly what's wrong. I feel as if maybe it starts rolling too soon after landing - I can't explain it, but it looks as if the ball is sliding more than anything. Perhaps the rotation doesn't quite match up to the speed of the movement? Maybe it's the timing on the movement?
The initial drop seems a bit too slow as well - the ball lacks any real weight and I think some of the successive bounces need a bit of tweaking as well. They're a little choppy? Overall, I'm not too sure about any of it - the ball, to me, doesn't seem to carry any particular weight of character. Maybe it hangs in the air too long as well?