We stay at Constanca's place for the World Cup Final weekend and it was great. Constanca speaks good english, is very helpfull and enthousiastic.
The room is clean and perfect, as well as the bathroom.
The location is perfect and very safe! It's a few minutes walk to the Copacabana and in the area are a lot off nice bars and restaurants.
The building from Constanca's appartment is also protected by a security-man.
A great stay at a great host!