How much have you been sculpting? Looks really professional and the likeness is damn solid.
One thing though, if it is okay to make suggestions. The hair looks a little swept back and not just short and straight up - more like the T1000 style, if you know what I mean. A way to counter that effect, I've learned, is to basically stab the tool down from above to create that straight-up hairdo look of a short trim. But seriously... it's cool already - I just think that would add to the piece.
3rd scale. Hmm... always wanted to try that size.