We had a lovely stay in Federico's appartment. We did not meet Federico in person, but were welcomed by Maurizio, who was very easy to reach. The appartment is perfeclty located: Trastevere is a very lively neighbourhood and situated closely to the centro storico. Because of the lively neighbourhood, I do have to admit that the night could be wuit noisy with people passing by (the appartment is on ground floor) and other people/guest entering the building in de middle of the night.
Overall a good stay!