IMO Cotto is good but bot as talented as the others. More predictable. Mosley has revived his career but may well be at the beginning of downward slide. Pacquaio is moving upward but Mayweather and Marquez are at their peak.
Mosley's revival is in part due to a nose operation to remove inside scar tissue so that he could breathe better..before that he had trouble in late rounds. Marquez and Mayweather dont have
similar stamina problems in late rounds.

BTW championships are 12 rounders these days... 15 in Sadler's time.

In any case the welterweight classes are filled with talent- compared to the lightheavies and heavies, currently.

joy chaudhuri