I think it's important to say that your diffuse has really come a long way. Everybody's critic is accurate, but you should know you're definitely on the right track. Maintain the course!
You could combine some of your texture maps into other files if you have not done so. It would save on space and you can break things down once inside the material editor in UDK. You could combine the spec and glow into single channels of one map or into the alpha of the diffuse, etc. Your emission map should be a plain…
Looks good but I have a few criticisms. I'm not a pro so don't believe everything I say. as far as the model goes (maybe not relevant to you, but whenever I make a texture I make sure the model is optimised) the smoothing groups are a bit odd in places (cannon, metal pipe). you're also using a normal map but you didn't do…