Comparison between Waffles and Mizu? Hmm, let's see..
Waffles can pop out just about any stick his imagination has, given the good movements and fun to watch style he has-regardless of how silly it looks- he's much superior to Mizu because the most thing he can animate is anime-based animations. From what I've seen from him anyway.

If you talking about the best pivoter of all, I wouldn't say that's possible to know because that term is pretty vague. Everyone has his own taste of animation, some people like it smooth, some like action-packed movements, some people like to see originality and don't care much about how realistic the movements might be. So, try to be more specific when talking about the best pivoter. Do you mean best combo maker? Most creative animator? The one with smoothest style...?