Going with the rest here. Cintron is a harder puncher in terms of 1 punch, Cotto is a better puncher and I would say he's physically stronger than Kermit.
Cintron is definitely the bigger puncher and his punches are just as composite. He's just more inconsistent with his placement because he lacks the discipline to follow a gameplan like cotto does.
Cintron might look like the bigger puncher. But I think that is because of the level of opposition they have faced. I have never been impressed by Cintron. I think he has a very basic 1-2 and thats it. You have to stand there and no move so he can't hit you. Margarito demostrated Cintron don't know what to do if you keep throwing punches at him. And the only head movement he has is to put his head between his legs. Heavy hands but he doesn't have the tools to use them. Cotto is a very different animal!