I've been experimenting doing architectural V-Ray renders during downtime at work.  The lighting and rendering system seems a lot more intuitive than my experience lighting with Mental Ray, what you expect a light to do in a scene seems much more predictable with V-Ray.  I modeled the room, but most of the objects in the scene were downloaded from turbrosquid or other free model sites.
 day
night 
overcast 
TV illumination 
composite