My sister and I go to Vegas 3X a year. We have always stayed on the Strip at different Harrahs properties, usually fully comped for our rooms.
We took the shuttle over to RIO one Sunday prior to leaving for home, and we absolutely loved the atmosphere. It is a loud, festive casino with live entertainment on little stages scattered throughout. The beverage servers are fast, friendly, and the thing we liked is that they have MALE servers that treat the ladies very well. Never a dull moment at this casino.
We will be making our 4th trip to RIO this summer. It is an easy walk to the strip, or they run free shuttles every 15 minutes. The pool is amazing, the rooms are very nice with great views, the service is excellent, the restaurants are great and have a lot of variety.
The gaming is above average, better than the Strip. Highly recommend this casino/hotel. If you want peace and quiet, however, this probably isn't your place.