I agree. This is very nicely done.

Good shading, except the darker outline on top which is inconsistent with rather top-down light. See this ref. The lower jaw might be a little more in shadow, for atmosphere more than consistency; and don't forget the resess between teeth and chin.

You might also break the mirroring a little.

Nice piece anyway!

 I think I softened them a bit better now. 
I like to save the progression of pieces I work on, and looking back I can't believe I thought it was done where I did. 

Your help was invaluable to me.

I think the corners of the eye sockets (and around the nose) could use some light aa, that areas so dark it more easily creates jaggies. Great job here, came a long way since the first draft.