I noticed several differences when I saw the raw model for the first time but I prefered to keep my mouth shut because I can’t make a better model myself, can I?
OK, the overall shape of the original is somewhat steeper from the cheek bones towards the chin.
I made up this diagram to make things a bit more clear.
http://img519.imageshack.us/img519/792/untitled1an2.jpg
Also the chin itself is more squared up on your model while it is softer and a bid more rounded on the original.
It is not that pronounced and does not stand out that much as on your model.
The nose on the original is more rounded and a tiny bit fatter.
It is more pointy on your model.
The eyes on your model are looking too far right. The guy looks cross-eyed or like he is performing a trick with his eyes to make his buddies laugh.
Another thing: the lower lip seems to be thicker on the model.
Hope this helps and please don’t kill me. 