In my opinion the v1 sculpt is pretty bad. Like a bad sculpt all around from the size to the skin color to the pink mouth to the expression to the likeness.
I reckoned it was the height of the forehead and height of the hair.
I did a simple dremelling of a head and tried a plasticene resculpt with it lower and i reckon it made a bit of a difference.
Not a huge difference, but a difference.