Nice mesh. I have a serious problem in making such clean meshes and I admire people who has this ability. He looks very tough, exactly like a Commando soldier should be.
When I started doing my entry for this challenge I was using Zbrush for studies, and for help me in modeling. But much people didn't like. I hope you don't face this kind of problem. Problably I will use Zbrush for color maps, since Photoshop painting isn't so intuitive as in ZBrush. Good luck in your work man!