First let me say this has a very photorealistic look - almost like a picture of a model. Since you want critique, I'll give critique and this is all IMOO...
(As you are constantly raising the bar, these are getting picky, I'll admit)
-Overall the image is dark. This could be the old laptop I am using, however.
-The roads look a bit too soft focussed (but that could be the intent if representing dirt).
-Not too sure about the horizontal banding on all the roofs.
-Most trees are much taller than single level dewllings. Their drop shadows should be more displaced.
um. Thats about it from me! SO how long does it take (as speed was one of your intents)?