Size and speed still matters. Skills are important, but Duran had that and still went 4-3 at the weight. Really good wins at 154 and above were a bonus for Duran, but not the kind of thing that could be counted on regularly. I'm going with Sergio on points. A 154 Duran really doesn't match up that well against him....a more stationary, slower slugger, I could see. A faster, more mobile fighter who can pop and has a size and massive reach advantage? Not Hands of Stone's best style to face.
Martinez can move and punch very well, this does not favour Duran. At 154 Duran is not the beast that he is, he will have to outsmart and counterpunch Martinez but I dont think Duran could keep that up for 12 rounds. Martinez UD