Mosley is not as fast as Floyd. And I also disagree with what everyone seems to be saying: "Mosley's not as fast, but he's the closest thing to Floyd in terms of speed. This should be rephrased: Mosley's the closest thing to Floyd in terms of speed who is available to spar right now. Zab is undoubtedly faster than Mosley -- from the opening rounds of the Zab/PBF fight, it's possible that Zab's slightly faster than Floyd at 147.

Of course, Zab's not available to spar -- and would probably be a terrible person to have in your camp for numerous obvious reasons.