A few people have said that the hand looks too big; personally, I don't think it's the hand itself, but the wrist looks a bit thick compared to his hand and the rest of his arm, it's not much thinner than his bicep. If you made it a bit more slender, the whole arm would look better proportioned.

It's such a little thing, though; it really doesn't detract from the image as a whole. And I love all the lines in the back of his hand and forearm; you can see that the muscles tensed, it gives such a delicate figure so much inner strength.