This is a nice looking sculpt, however since you asked for precise criticisms. I believe the overall head is a little too thin, from front to back. The rear of he cranium should be a little more full. I also think the mouth and jaw line are a little too far forward which causes the nose to be a little elongated and large. Finally the upper eyelids are a little too smoothly circular and might look better with more of a parabolic shape if you know what I mean.
Having said all that this has lots of very nice touches to it already.
John