TLDR: Most likely my best experience on AirBnB so far :)
Joao's place is located in one of the best neighborhoods of Rio, Urca. Close to Sugarloaf and a couple of beaches, also has a couple of places where locals go out. At the same time it has a quite suburbia feeling and the best safety record in Rio. The apartment was spotless and had everything we needed to make our stay perfect (including 2 ACs, one for each room!) You would be hard pressed to find anything of this quality for a similar price.
Last but certainly not least, Joao was a great host. Responsive and helpful but at the same time completely unobtrusive. And since he lives just above always a stone's throw away if you need something. I will gladly chose this place for my next visit to Rio.