i'm sure you did a good job on rendering this picture, but the original has very crappy hair, so on the dark-background of GR it looks even more crappy (because the dark parts aren't visible). You might want to deviate from the original, and make the hair a bit more smooth, i think it'll look better that way.
The hair was something white spaces between it...but the rest is very good. A great render!=D -Exxodus