would you mind sharing some of your settings? mainly final gather settings and maybe one of your basic material setups? I would like to experiment and see if I can't get a similar atmosphere to your shots with the big project I'm working on right now.
I've been using mental ray almost exclusively since I learned max a couple years back, but I only started using the arch&design materials a few months ago. It's always helpful to see what someone else did to achieve a certain look.
Either way, masterfully done!