We usually stay at the Rio on each trip. (We visit Vegas 3-4 times a year) I would say that the Ipanema Tower seems a tad more updated. They are more centralized to the main casino area too. However, we usually prefer the Masquerade Tower because we have a rental car and like parking in the garage closer to the Masquerade Tower. It just seems more convenient to us. As for best rooms, I would say Ipanema only because they seem more updated. But we do enjoy the pool view or strip view rooms in Masquerade. If they give you a big upgrade, maybe take the Palazzo suites!