Thanks for all the feedback and comments!
I'll be keeping the crop for a number of reasons. One of the things I will comment on is that "light and airy" is certainly not a feeling I wanted to express through this shot. Also, the subway environment is something I wanted captured here, so the room above the head was intentional. Giving a sense of location is necessary to me in this sort of shot, especially since I met him and stopped him for this shot in this location.
Not to say that there aren't valid reasons for other's opinions, but to me a crop would take away from this shot.