I'd personally say that the shadow of the crown looks a bit too messy. Then there's the pitch black shadows of the hair which make it seem like the hair has been extended in black if you see it on the white version.
I wanted to give some steel effect to the crown so I've decided to use lighten tool. Maybe that's the reason why it seems messy with these sharp lines on other details.
About black hair: I wanted to make it smooth and deep colored which is hard to do using black gamma (as for me).
I think it's not evident on a sphere but it makes black hair deeper.
skin tones could use some more contrast, the shadows around the eyes especially are crying to be darker, would give it some real character.
otherwise yea, its pretty nice.
I thought about using more contrast on the face. I suppose this was my fail that I've used only light colors on the face (except of black). I caught too hard about the wishes of the customer to make a very bright face.