I like both fighters, but Cotto is the future while SSM is winding down his career, plus I really, really want to see PBF-Cotto at some point. So I picked Cotto.
I think SSM is going to win though - too fast, too experienced, and I'm willing to bet he hits harder than Zab, who shook Cotto in their fight. Plus SSM is a better finished than Zab.