Pacquiao has a legit shot to end this within 3 rounds. If it goes beyond that, Arguello starts to take control and catches up on the cards. Very possible he stops Pac, but I feel Pacquiao at 135 is tough enough to last the distance. Probably an 8-4 type decision for AA (not counting any knockdowns)
Alexis is the better boxer, and I usually favor the boxers. But along with his amazing boxing brain, he had a full arsenal of picture perfect punches, lethal power and deadly accuracy. Pacquiao has the speed advantage and reflexes, but I see him ending up face down around the mid rounds.