Interesting subject. I would actually crop more. You have his head like absolute dead-center in the frame which is often kinda "meh" and you don't have our focus zoomed in on him enough. I would AGGRESSIVELY crop so we're in really close on him- possibly even so his face takes up like 1/4 of the frame. I would put his face more in the upper left, perhaps... it's a bit hard to tell with a smaller image like this, but I think that would give it more oomph.