We stayed at Thea & Gui's apartment (Ipanema) in March 2013. It's location is great, really close to Ipanema beach, and a couple of blocks from Copacabana's. The street is very nice and calm, with nice buildings, stores and restaurants just around the corner.
Although the hosts couldn't make it in the city by the time we stayed there, they arranged everything perfectly, and the doormen were very kind and helpfull with us (24hs in the lobby).

Talking about the apartment, it is a great option. It's so charming and beautifully decorated. I highly recommend it because of two big facts: it is very luminous (walls all white and a good size window in the sea side) and it's perfectly cleaned, everything was just in an excellent condition, even the sheets and towels.

In summary, we had a great stay, and if you want to stay there, just don't have any doubt about it.