As a plumbing inspector for a major building department in Ohio, I can tell you why the sewage smell is so prevalent in many "high end" buildings like the Luxor...Their money and prominence allows most of them to get away with not meeting the minimum requirements of the code, which in many cases they do by promising to fix certain inadequacies, and never do.
It truly makes me sick to see how much is "given away" by political leaders and chief building officials when it comes to high profile jobs. I realize this could be a case where well meaning maintenance personnel have done improper work on the mechanical system, but often times it is flawed from the very beginning.
Thanks for allowing me to ramble......