I'm not sure about the composition - it seems he is looking out of the frame and there is unneeded negative space on the right side. The detail on the man's face is good, the skin tone looks a little off though.
might have been better to position him at he right side of the frame, space at right has an empty and useless feel to it. Like the almost monochrome look and the DOF, dislike the overfiltering (probably shadows/highlights), that produced a halo around him