Positives: The apartment is very centrally located, with major attractions within walking distance. Despite being in a busy area, the apartment is very quiet and the building is secure. The owner was very nice (waited for us although we were late because of a car accident) and left us a bottle of wine. The small washing machine was a plus.
Negatives: The apartment suffers from some deferred maintenance. Lights don't work (over the stove, in the main room) and faucet caps fall off when you turn on the water (in the kitchen and bathroom). Most unfortunately, the bed is VERY uncomfortable (worst of our six week trip in Europe) so we slept very poorly all three nights. Lastly, you really need to have a local phone to get in touch with her (which we didn't) as she doesn't answer email very quickly (we tried to get in touch with her while we were staying there).
In summary, the apartment is in a great location and we enjoyed staying in a different area of Rome than we usually do, but we would not stay here again.