1) It's no fun when two boxers you really like square off. Boxing tends to personalize the connection between fan and performer more than most sports, and watching two guys you genuinely like in and out of the ring must be a bit like watching two family members throw down. I was bummed before it even got started.
2) The revelation of the fight (besides the new photos of Margarito's hands) was that Pacquiao can take a welterweight shot. Offensively, Cotto did a decent job (although there was not enough jabbing or body-punching), but even in the rounds where put everything together, he never had Pacquiao in any trouble.
3) Pacquiao's body of work is by any measure historic. I'm not saying that he'd beat everyone from the Sugar Rays to Henry Armstrong to Joe Louis (but surely someone on some boxing forum is making precisely that argument), but the number of wins he has against hall-of-famers in different weight classes is absurd: two against Morales, two against Barrera, and one each against Márquez, De la Hoya, Hatton, and Cotto. (The last two, especially Hatton, aren't guarantees, but I'd guess they both get in.) And that's all before his 31st birthday, and he's still getting better. You can argue that a lot of these guys were on their way down, that he was extremely fortunate about fighting in an era where there were so many great fighters, and he was lucky to beat Márquez, and you'd be right, but whatever, he could wind up beating ten hall-of-famers. That's insane.