Mosley proved in the Forrest I fight more than anything that he has heart and a great chin. Forrest headbutted the hell out of him. I don't know if I've seen a worse headbutt in any fight ever. Forrest should've been able to get Mosley out of there. Had that headbutt not landed (not saying it was intentional), I think Mosley would've won a forgettable fight, no rematch, and would've kept undefeated for a while at least. Easy to say "if this, then this" I know, and no way to really know. Point is, Mosley could've folded, could've probably even had the fight stopped due to the headbutt. No, he fought back and survived the distance. Then he went immediately in for a rematch, no tune-ups. I thought he won the rematch, though it was close, but whatever. He clearly lost both Winky fights, but even after the first loss, again, showed heart by going right back in against Wright. It wasn't smart, but it was heart. There's no questioning Mosley's heart, imo.
That was Mosley against Wright and Forrest. Cotto hasn't had to come back against people of that level. He had to dig deep against Corley and Torres. Mosley has never been in trouble with guys on that level. So there is that to consider. Sure, Cotto could come back against Torres, Corley, but could he if he had an all-time great beating him down? Maybe he could, but he hasn't been tested like that yet.
I'd favor Mosley b/c of his style and experience, but wouldn't be surprised if the younger, more hungry Cotto beat him. I think Mosley would've dominated Trinidad. There's often comparisons made to Cotto and Trinidad of course, but I think Cotto has a significantly better shot against Mosley. That's not to say Cotto is necessarily a better fighter than Trinidad, just his style is better to face Mosley, imo.
I'm favoring Mosley, but I'm still calling it a pick'em fight. I don't think Mosley will lose by KO/TKO, too good of a chin, which says a lot b/c Cotto can hit damn hard. I think DLH hits at least as hard, Vargas likely hits harder. Mosley isn't getting knocked out unless he just comes in really old. Could see Cotto getting stopped late, but I'd really lean more toward a Mosley UD, around 116-112.