thanks for the polypainting demo! it was enlightening. That head looks a lot more natural compared to the previous ones aswell, it has great character.
It feels like there's a few repeating patterns in your heads (the cheek bones being the most obvious). I also tend to do the same facial features on each head I do, by accident, specailly if I start with the same basemesh. It could be a style your doing, but as I am aware of it in myself, I thought I would point out just incase