I stayed at Marta's place during my Erasmus in Rome and it was really great! Marta and her daughter Elena are some of the nicest people, and nicest hosts, I've ever met and they were super helpful every time there was an issue or I had a question. The apartment is small, but big enough for one person to live in comfortably. The size of the kitchen gets a bit frustrating after a few weeks, but it doesn't matter so much when you can eat on the balcony ;) The area is pretty quiet (for Rome), it felt very safe being there and you can get around very well on foot (if you don't mind walking up the hill to get back). The only downside to the location of the apartment is that it's not close to the metro, but there is a train station close by, a tram not terribly far away and a bus.