This is definitely an awesome picture, that global shading is a very handy option isn't it? x3. I love how simple the architecture is and how the coloring textures and lighting make up it's awesomeness. Very nice work :3.
Question- are the buildings in the foreground larger scale than the background ones? and i like that -land sloping- aspect of it.
I'm also curious about that blue, blocky look on that foreground building and the blurred far background buildings..did you actually have buildings all the way back there?(if that's the case..that's ridiculous..lol)
Render time? Forgot. I'll check for very precise time - I must have it somewhere - but it's not long at all for the moment. Arround 1hour maxi for 2000px on a quad, with a correct AA setting, but no reflection/refraction or whatever slowish stuffs. Well, even so proxies don't use ram, there is still lotof geometry to be computed by GI