The first one is very good, I especially like the walls subtle reflection.
I don't know for the second one though, the darkness might be intentionell, but the extreme yellow tint makes it look kinda weird (well, for my taste). You could lessen that effect by adjusting the turbidity below 3.
The perspective in the third image is a little off, it is obvious that the background picture has been taken with a entirely different lens than your rendered image. yours look extremely wideangle and your perspective lines would intersect below the horizon line giving your building a little "downhill" feeling.

Other than that, it looks great.
Regards,
Benjamin