Wow, I've been looking for a map like this forever! The map looks really nice and feels quite nice throughout gameplay. It also has some great lighting, how the heck did you do it?
However, there are some minor details in this map that should be added:
First, the map needs a 3D skybox, for that would make it really nice looking, and practically perfect it.
Second, the map needs more cover in the middle section. I've noticed a lot of maps these days don't put cover in the middle of the map and focus on the extremities. Thus, as a result, people can't stealth way up to the other side or go from cover to cover.
Finally, the underground section can be expanded by a lot. It just simply makes for a killing spree right now. Add more paths and other things and that, with the other two points would make this map perfect.
Great work, I feel that this map shows some real potential from becoming quite a good one. This map shows elements that all maps should show, but unfortunately, unlike yours, they don't!