When working on heads don't use a simple blinn/phong to view your progression. Use a shader/matcap/light solution that let's you see the head
with fall-off mimicing more natural light conditions. We tend to see people in an environment where the light wraps around from all angles
and there is a certain 'lit from above bias' (sun in the sky, lightfixture in the ceiling etc).
Here's a quick photoshop mock up of what such a shader would make this head look like.
I feel your sculpt is a lot better than what your printscreen currently suggests.