Here is a project I did awhile ego (as a student project). The purpose of this project was to integrate CG element into a live footage. I tracked the footage with a tracking software then I did the 3D modeling in Max 6.0 and later on composited the whole thing in After Effects 6.0. The final resut can be seen at:
good tracking indeed, and nice contrast-matching.
but too bad that you had to change so much the colors of the original photo. I guess it's because of the 3D elements - they are not so good, in that the face looks like a computer-games-dude (the texture and shading is very simple, but more important - the facial expression is static, puppet-like), and also the "metalic" robo-elements lack detail, and... hm, flavor. another problem, I think, is the "cut" - where the flesh and metal meet. looks plastic and too simple.
the post-processing has seriously affected the natural warmth of the photo. that's a pity. although you can see that in many movies...