Stylistically Floyd is pretty bad for both, though Ike's offense would have Floyd on the defensive all night long. I just think Floyd would control the pace, as Ike was never much of a pressure fighter and was often content to box it out, which is why I'd favor him over many more pressure fighters/swarmers than pure boxers.
As Sweet Pea said, Floyd holds the stylistic match-up over Williams, although it would be interesting to see how Mayweather delt with someone who could be so explosive. Floyd, due to size should be physically stronger than Saddler, which would mess up his gameplan.
