That is some stunning flesh work mate, you are definitely upping your game with every face you do, cant see where you could improve any more on this one.
Had to do a double take thinking I was looking at a photograph of someone and not a model. Have you mastered (unlike moi) the art of working with acrylics or is that oil paint? Love the 'wind burnt' complexion. Spot on!
I like a lot the skin tone. It's very realistic, the expresion of the face is very good too. For my taste i could try to get more constrat, but if you like it in that way is again great job. Only thing I do not like so much is that the eyes are too small in my opinion. If you look at your eyes in a mirror, the white part (i do not know the name in english sorry) is only around 30% of the eye (15% each side), that means that the iris is around 70% of the visible eye. You painted it maybe half of it's side.
But please keep on the good things you did