I believe that Stahlberg uses Maya and uses the occassional n-gon and tri. Check out this thread:
Your mesh is looking better, but I think you should improve the edge loops. I will try to explain what I mean: Right now the edges that form the detail under the eye you have go over the nose. This extra detail on the nose is unnecessary. Instead, have the edges circle around to connect with the edges detailing the upper eyelid. You will also want to have circles of edges around the mouth. If you aren’t planning on animating this model, it may not matter.
If you’re unclear on what I’ve said, have a look at my model. Although I am sure that it is far from having the best topology, I do have loops around the eyes and mouth so you can see what I mean.