Cotto gasses, Floyd gets stronger as the fight goes on. Cotto is one handed fither and Mayweather is one fo the greatest technical fighters of all time. Cotto is flat footed and cuts and swells easily. Mayweather is statically the msot accurate puncher ever. You do the math.
It would be a chess fight, and we all know Floyd is more skilled than Cotto. If it's at a slow pace, then it's a chess fight.
Margarito is like a target practice. If you can find a way to avoid his slow barrage of punches, then you'll be able to land 50% of your power punches on him easily. Cotto looked great against him, but it would be a totally different dog fight against Floyd.
I think the fight would be interesting and we should claim that fight as a second choice after Floyd vs Pac. I think e fight would be interesting for the first 4 to 5 rds and then Floyd will ultimately take over. But I'll be rooting for Cotto