The Rio Othon Palace is the kind of palace that belongs to the black-sheep duke who gets no tithe from his peasants to keep the place up! At the time I was there, the whole thing was shabby, from the lobby (stained and threadbare couches and rugs) to the hallways (carpet so worn down it could have been linoleum) and a room so dated I felt like I was in an original episode of the Charlie's Angels. I suppose I would have put up with this if I felt I was getting a deal, but I really overpaid. While the concierges were very kind and helpful, they still tried to sell me packaged tours. Also, they refused to hail me a taxi, but insisted that I always take their car service everywhere, which was totally overpriced.
However, my room did have a gorgeous view of Copacabana beach, and it was five minutes total from room to shore (which made it easy to lie on the beach even when I had only an hour between appointments). I did seem to notice too that they were renovating the place floor by floor. There was a rooftop pool next to the restaurant (which served a decent mozarella, tomato and basil sandwich).
To sum up: there are many other places to stay in Rio that are on the beaches that are a better value or just better-kept.