Speaking personally, the arena itself would never be much more than a render plaything for me. I would not attempt to fill it with anything like a realistic crowd. I can imagine that a comic-style 2D crowd overlay for the seating areas would be relatively easy to set up, or even a bunch of low-res figures; but this sort of scene is (at least for now) not something that really appeals to me.

A hotel room would be of much more interest, not only to me but in the Poser marketplace, I think. If it is cleanly and realistically modelled, imports well into Poser (no smoothing issues, etc.), and has good material zones for flexibility in texturing, then I think there may be a rewarding level of interest. It would depend a great deal on the price point, of course. As you know, Poser products tend to be way down the price and quality scale compared with those for the higher-end apps. With notable exceptions, I add hastily.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)