So, I don't actually have too many pictures of this guy, or they aren't quite the ones I'm looking for, so I'm going to create the BG specifically for my profile page.
it looks fine. the only thing I'm really noticing is that the shown hand on the man on the left needs a little more depth through the palm (I think?). Also, the eyes are a little bit small. I'd say they only need to be a few pixels larger, and then moved down a few pixels as well, but since you've already moved on to coloring it's not really a necessity and it looks fine as is. Otherwise it looks very good, and I really like the attention to detail!
One thing I noticed though is that the shoulders seem a bit narrow for such a B.A. manly man.
You may be able to fit it up with a bit of cutting and stretching, or liquify or something.
Also, when you paint hair, try to think of it as chunks first, then individual hairs (and not as many of them). I think the rest of your painting is too sophisticated for the way you paint your hair right now. Think big shapes to smaller ones.