I'm in a video game development program at a local community college. We used Sketchup in our intro class (I took it Fall '10 semester)...I really didn't like it much. But what you've done here is really awesome. I can even tell which techniques and tools you used on most of your model. I agree that Sketchup's textures are really flat...but have you looked at the Indigo renderer? It has a plugin for Sketchup and it's totally free (as far as I know). They have a commercial version but the free version gets some great results. One of the guys in my class used it and it turned the models from cartoony to really nice. You might want to look into it if you continue using Sketchup a lot.

I never really considered using a 3D program to make maps, but this isometric model gives me a lot of ideas. Thanks for posting! I'm giving you rep.

Wisemoon