Wow, looks wonderful. My favorite part is the detail on the head thingy. However, the detail tends to fade as it moves down below head level. He does have some pretty thin legs, and arms are a little strange also, but that shouldn't matter since it was the line art to be colored/chosen any way. Don't think there was any way else to shade the guitar, seeing as how that's how the texture of a guitar should look, in my opinion. The only thing that could possibly change with it, is the shine, which is my biggest concern.
Why is it, his shirt has some red/pinkish back light shining on it, however, his pants show no such detail? Otherwise, great detail here...