Stayed 5 nights at Mandalay Bay hotel and traversed the casino on multiple occasions several times per day. If you like smoke filled stale air and lots of room between barely used gambling tables then this is perfect for you. However, if you prefer the company of others and clean fresh air then go to The Bellagio or MGM Grand Casinos which I did during this same period of time. Somehow the cigarette smoke still finds its way up the elevator and into the "smoke free" rooms at the Mandalay.