I only ask since I still get offers from Circus,Circus. This dates back from our first convention in 2005 and I spent a few evenings across the street from the Riv at CC playing for silver strikes.
I know the casino floor is "tired" and the buffet is consistently rated one of the worst in Vegas (we can attest to that, just awful!!). BUT, the West Tower (closest to the lobby and the parking garage) renovated their rooms a year or two ago and they are actually quite nice....new shower/bathtub combo, marble topped vanities and furniture, flat screen TV, nice linens, etc. And often a view across the street towards the Riviera.
Also, when you check-in, ask for an "adults only" floor (I believe most of the West Tower is adult only) . No sounds of little feet and screaming down the hallway, you'll thank yourself if you want to sleep late in the morning.
One time I got a little spooked/suspicious at the amount of teenagers hanging around in the parking garage, and just pulled into valet across the street at the Riviera. No problem picking up the car the next day.