We (I and 2 girlfriends) stayed for only a weekend at Fausto & Gabriela's place and it was a great choice for us. The apartment is very nice and quiet, it has everything you need for a short or long stay and the terrace and garden are lovely. Also, it's located right across the street from a Police station, so, needless to say, we felt very safe there with all the carabinieri :) Our hosts provided all the information we needed, recommendations for places to eat and visit and, because we had some very hot days in Rome ( 33-35 Celsius degrees), they even brought some fans they especially bought for us to feel more comfortable. The only downside is that we didn't get to have a longer stay in Rome :)
All in all, it was a great experience and, if I return to Rome in the near future, this is surely the place I'll choose :) Grazie mille, Fausto & Gabriela! :)