This is a great option in Rio, for a number of different reasons:
1) Location: Gavea is a great place to be in Rio, and the apartment, though in a very busy area (lots of restaurants / commerce nearby), is very quiet. It's also a few steps from Jardim Botanico, my favorite place in Rio
2) Host: Cristina is a great host. Organized, responsive, caring, really above and beyond the usual hosts.
3) Apartment: though small, it has everything you need (and everything works properly). Mattresses are very good, the decor is nice, you will really feel at home there.
Highly recommended!