Bers' edit is amazing, as usual. I was going to say as I was scrolling through your steps that the arm that Bers corrected really looked too broken up into the separate muscles/regions and looked... disconnected. Even with Bers' edit, the upper region where the shoulder is still looks disconnected. I would suggest trying to get more of a graceful curve going on along the upper edge of that arm.
The head is a bit too small, I agree, for the body. I also think the little bit of muscle at the bottom left (our left) of his torso should be trimmed a little. The area around the elbow on his right arm needs to be changed. Here's what I think it should look like, but I could be wrong:
The hand on the same arm I edited also seems off to me, but I'm sure someone else could address it better than I.