Ortiz was 135 pounds and so at his best his resume is greater than Cotto, different weights so head to head is a wash. Ortiz is the greater fighter. Although Ortiz fought at 140 he was a true light weight and Miguel never fought at lightweight which is Ortiz' best weight. A better comparison would be prime Ortiz vs prime Chavez at 135.
Ortiz fought at 140 numerous times throughout his career, won the championship at the weight before his move down and ATG 135 reign, and fought great fighters there in Loi and Locche. Also not to mention that he was a beast of a light weight. He was better at 135 but he could do more than hold his own against the very best at 140. Anyway, Ortiz is the superior all around fighter here, strong as a bull and holds great advantages in chin and stamina. He grinds Cotto down and stops him.