Would definitely recommend staying at Cristina's apartment! We arrived to a clean, surprisingly spacious apartment, with everything as promised.
The street front was clean and safe, with taxis readily available at all hours with reasonable fares to get to Lapa, Christo Rendentor, Copacabana, Pão de Açucar etc.
Cristina was friendly and very helpful when we called with questions and if we come back (from Australia) for the Olympics next year, we hope to stay again!
Thanks again, Cristina :)