I don't know where these other people have stayed in Vegas, but the Rio is HORRIBLE & DISGUSTING if you're used to any of the following: Mandalay Bay, the Hotel, Venetian, Palazzo, Wynn, Encore, Bellagio, Paris, etc..  It is not classy, the rooms are old and basic (corner suites are barely okay), the service is tired and staff almost seems to resent working there, the casino is small and gets boring fast.  I'd compare it to the Sahara, except the Sahara has a better casino.  Stay at the Rio if the price is right and you're not looking for luxury, but just know what you're getting.....