The location is perfect for exploring the main sites in the old town. Be sure to wander around the immediate area. Just up the street is a large and popular Piazza and an atmosphere quite different from the old town. Also there is an abundance of restaurants around the area.
The apartment is as described, but beware of having heavy luggage as you have to carry it up a few flights of stairs.
If you are driving, be aware of the congestion charge in that area.
The terrace was very nice, and Fabiana was a very responsive host