I would have to go with valero, I respect khan and think he's a good boxer I don't hate him whatsoever. I just believe that Edwin being southpaw obviously produces problems from the start and Edwin has equal power in both hands and moves around fighters and would most likely employ what he usually does which is varying speed power and timing on the fly and would beat on khans arms chest neck and everything. I give it to valero for being a talented and still growing fighter. I believe if valero was a pure boxer he would lose via unanimous decision but his killer instinct, speed, power, attacking all parts of the body not simply aiming for spots he would break khan down. I see late stoppage or flash knockout.
I wanna think Khan has gotten better since his KO from Prescott. But I think Valero would've been non stop and eventually would've wore down Khan, maybe mid-round KO.
I hope Khan can make me a believer though.