I like the architecture- looks to me like you've done a nice job of working off the concept art while adding in your own touches here and there. When I look at the buildings I think, oh, I wonder what those are, instead of, oh, I wonder what those are supposed to be. I'd call that a good distinction between an object and a building. :P As you mentioned, textures aren't final, but some detail work could result in a very nice looking building facade.

The map layout sounds cool as well. I'll be interested to see what the rest of it looks like.