Bit too big for my liking, but meh, thats personal preference. I think the black and white rectangles could do with the opacity lowered slightly, since they seem totally random in the piece. The random grunge spots in this piece with the clipping masks don't suit it in my opinion. No real depth or perspective, which is a pain. Try blurring or dodge/burning parts of the background to see what you can come up with. The render looks like it has a outer glow around the head, which looks bad in my opinion. It could do with some sharpening up though. At the moment i don't think it blends as well as it should do. Try duplicating the render layer and playing round with the blend modes and opacity.
Ahh, Saw this guy live a couple years ago when I saw a Van Halen concert, he's awesome.
Anyway, nice sig. A bit simple and could use more blending. I agree with the above critique, but still nice~