First critique!
So let's get this show on the road!
First of all, I'd like to start out by saying that this is a really amazing piece of art. I love the depth you gave to the hair, especially with the light reflecting off of it, giving it a sort of metallic look. Also, I think the shading on his face and neck is really good.
There are two things I think you could improve on a little though. The eyes seem a little flat to me, and the lines of the hairline and the top of the hair seem a bit messy compared with the clean lines of the rest of the face.
Keep up the great work!