I checked your model out.
You have many duplicate vertices which you can get rid of by going into edit mode and selecting all vertices and pressing W>Delete>Remove Doubles. You can also do the same but press alt+J to convert tris to quads which cut down a decent amount.
I was able to get you from 58,447 vertices with 63,824 faces to 46937 vertices with 52,448 faces.
About 12,000 less vertices and faces.