I`m planning to use realtime SSAO in the future to see how it comes out.
Some progress (Blender 3D view). Still far from good-looking. The whole level has 48k Faces so far including vegetation (not that much right now). All buildings together are 28k Faces (about 30-40 med-poly buildings plus 50-70 lowpoly distant ones). I`m a bit afraid of performance issues, so my aim is to be chary with too much details and textures in the first place.