Seems alright to me. I stayed in the "manor" which is the motel in back of the main casino/hotel and i paid under $50/night for four nights that spanned a weekend. It's not the top notch service, shopping, dining that some of the other casinos offer, but since I wasn't planning to patronize any of those anyway and didn't want to pay for them, the "manor" at Circus Circus was fine for me.
Nonsmoking is available. Not on their website or numerous other outlets. You have to phone them and ask in order to book one.