The apartment is very nice, clean and spacious. There are three bedrooms, two with two beds, one with one, each has airconditioning. There's also two bathrooms, both with showers, which was very nice. The kitchen is properly equipped and there is a washing machine with a dryer. The neighbourhood is probably one of the safest in Rio and the beach (Cobacabana) is 50m away. All in all a very pleasent experience.
I should mention though that the host doesn't seem to speak English (we had two Brazilians to do the talking).