The Mont Blu is the renovated Ceasars Palace and is supposed to be really nice. I haven't been in since the renovations.
IMO the choice of staying in a place like the Marriott, Embassy Suites, or best, a private residence or condo comes down to whether you really want to sleep at a casino. I'd be the wrong guy to ask since I'd rather be on the lift when all the casino rats are sleeping. I also have come to really hate the cigarette smoke in those places. Its an ok place to visit, but I wouldn't want to live there.