This place is perfect. Located right next to Vatican and Angel's Castle, 15 min walk from Trastevere, within walking distance from all the major places of interest. The host is very polite and welcoming, told us everything we wanted to know and was highly responsive during the stay. Thanks, Sergio, Paolo and Daniela!
Recommended route for three days: 1) Vatican in the morning, Trastevere in the evening; 2) the Forum and Colosseum in the early morning, then have dinner and rest a bit, then buy something delicious at Campo di Fiori; visit some concert in the evening, 3) walk through Piazza Novona, the Pantheon, Trevi fountain, Spanish Steps and Villa Borghese. Rest in the apartment during the hot middays and dine in any ovlf the cool places the host suggests :)