Cotto has a better all around resume than Marquez, but that's really the only thing Coto has an advantage in. Both have been champions but Marquez was lineal champ at lightweight an obviously those 4 great fights with Pacquiao put him over the top IMO.
Both are great, I'd edge Marquez but only slightly. Marquez is the better technical fighter but p4p Cotto hits harder and is more dynamic. Resumes are damn close too, both men have lost some of their biggest fights but Marquez has managed to win a few more.
Cottos resume is far more riskier than marquez as much as i see it, the only difference is marquez got a cinematic win against pac, without it jmm is no world beater i guess:buttkick: