Here is the haps:
The food is awesome. Ate here 3x during my stay at the Rio. Had the Prime Rib, Black Canyon Ribeye, Chicken Wings (BBQ and Buffalo) and the burgers. All of them were solid. Prime Rib and steak were cooked to perfection, the wings were some of the best I ever had. The burgers were great, big and nice and juicy. Also, the clam chowder is a bowl of awesomeness. Add some oyster crackers and a little tabasco and black pepper and you are good to go!
The wait-staff was great, friendly and attentive, especially while dining at the bar area. Don't know why people say it is loud in the restaurant. I had no problem carrying a conversation with the people I was with.
All in all, one of the better "diner" type places to eat in Vegas.