Mayweather by close ud in 2008.There fight in 2012 was outstanding certainly won of the top 2 or 3 most entertaining fights Floyd was ever in along with the fights against Jesus chavez and Augustus but Cotto was certainly a level above both of those guys.It was great that a fight people had been waiting seven years to see lived up to expectations.
Floyd would've still won, one of the things that made their fight as competitive was that Cotto was a well adjusted JMW, Floyd was always "just there". At WW, it would've been far worse for Cotto, I think Floyd would've had a chance at stopping him. Cotto is an elite boxer, Floyd was "the" elite boxer. Disclaimer: I'm a far bigger fan of Cotto than Floyd but I'm realistic