This is a really lovely modern flat which is close to Trastevere and Testaccio, two of the most interesting neighborhoods in Rome, full of nice restaurants and bars, right next to the river and within walking distance from the heart of the city.
The other advantage is that it is within walking distance of Trastevere station which has a direct train connection to the airport.
For anyone not familiar with Rome it might not look central on the map, but it actually is really convenient and, if you do not want to walk, tram n.8 which stops near-by will take you directly to Piazza Venezia.
Luisa, the host, was very nice and even ensured we had some fresh fruit and some milk in the flat when we arrived. Little things that make a big difference!