Modeling is high, and atmosphere are pretty. I can be wrong, but it look like if you used MR Ambient Oclussion in place of GI pass, or a lot of Vray dirt material.
With regards to the image of the palace, yes, I used some Vray dirt material, but in fact, the more detail is given by the high rate of irradiance in order to enhance the ornamental details as the only source of light are the openings.