Human Face Modeling with Blender 3D

Some time last year I did create one model with box modeling first. It came out ok. Not great though. So I'm not going to count this. I can see this model is pretty messed up. The hair and most of the facial shades that you see comes from the UV texture.
Still, i'll post the picture for the record.

My friend was kind enough to give me his front and side poses for the reference images and feel too bad to have created something like this. Adding to that i made this a video out of this as 'Halloween special' :-)






I've been lately following Jonathan's Blender cookie's tutorials for modeling a human head. They are great. I created 2 models so far with that. Both these are polygon modeling.
Model - 1












Model - 2


With each modeling, the time it takes to complete a model is greatly reducing. I also think the mesh is getting cleaner with each model. Now I am more inclined towards polygon modeling.
Some of the things which i need to improve on may be -
Ears
Working with lesser number of vertices. I end up creating more vertices than required. Some parts of the mesh(particularly near the ear) aren't really clean.
I still need to improve on hair.
The first polygon model, as you can see - i didn't really know how to comb. Second is a bit better and with texture some of my friends were able to identify the actual person..!!
I also did put some shape keys and animated a simple facial expression with a scene in which i just have to show the face.