My wife and I have stayed at the Rio countless times. NEVER had a bad stay. Watch rates carefully -- you can get a room circa $30 more often than not, however this is offset by an onerous and evil "resort" fee.
If you like seafood, the Rio's seafood buffet is top notch. For general dining the American Bar and Grille is quite a surprise as well -- upscale.
Hash House A-Go-Go is a fun experience too.
There are several negative reviews here. They baffle me. Try the Rio. If price/stay quality is important to you, you'll like the Rio.