I spent 4 weeks at Benedetta's place in February, and found the space to be excellent. The location is on a fairly quiet street, yet is very central to the Duomo. The apartment is set back from the street, facing a pleasant courtyard.
One question I had prior to booking this AirBnB was the noise level, since I saw conflicting accounts in the reviews. In my experience, the apartment is generally very quiet, with no noise from the street, but does allow in noise from the neighbors in the evening. I did spend a good amount of time working at my computer (there is a nice work space set into the wall), and was never distracted by any noise during the day.
Overall I greatly appreciated this AirBnB, and would gladly book there again in the future.