Martinez started boxing very late. You can't look at him the same way as a Roy Jones or other flashy guys who've been doing it their whole lives. He's a lifelong athlete but not a lifelong boxer, he's still improving, and his style lends itself to longevity, imo. Cagey guy who sets traps behind volume-powerpunching. Could probably go into his 40's if there's still challenges there. The punch will never go, nor will the craftiness. His speed might decline but his power can always increase to compensate.
English would put the world at his fingertips, but his looks already keep women shackled and on their knees.