first off, that looks absolutely amazing. Great work, and I love it. The lighting, textures, etc are excellent.
Now, my views of it as a graphic artist.
My one and only concern with it is the screen for the "Single" and "multi" buttons. They compleatly blend in with their surroundings.
Now, this may be a moot point with it in action, the text under it, mouseovers, etc. I can't really tell all those from a static image. But without the text, it needs contrast. Not much, maybe just 5 to 10% darker than the surroundings.
Again, great work man!