If anybody wants the model, you can download the .FBX and Textures at this link. I packaged it specially for Unity, but if you want to use it in something else just grab the Spec Map out of the Alpha channel of the diffuse map.:
I really wanted to make this mech look like he was made of different types of metal. A shiny chrome for the joints, a dull flat iron for some of the inner parts, etc. To achieve that I made some sharp differences in my spec map. Because my UV Islands were pretty clean, I was able to get most of this done in photoshop.
Here is the final result, with the spec map below so you can see how I got it to look like that. You can really see the sharp constrasts in lightness and darkness on the map creating the illusion of different materials used in the model.