Wow the realism is almost confronting! - in a good way - Exellent work! There are a few area's of concern :
The nose - I think it could be left just the way it is - however, I would personally provide it more structure, defining the cartlidge, soft skin better.
The eyes - I think are obvious points of conern.
Thats about it for now - looking back on your gallery, I did have more comments, but I decided not to add them until you've worked on the piece alittle more