I really like this image. The strong light against dark contrast makes it very effective. The only thing I would say needs to be improved is the detail on the arm. There is just a block of colour where there should probably be some subtle shading to pick out the muscle tone.

I like your style as well, but at least a little more shading on the arm would help. I didn't even recognize it as his arm until I read the previous comment. That aside, everything else is wonderful. The contrast does indeed stand out, and your shadows really bring out the shape of the face and particularly the hair. The mussed look of it really gives him a lot of personality. I swear, every time I see a picture of yours in the recent uploads, I have to look at it because I think it's a photo. Nice work.