Very nice apartment, and very quiet. Cristina and her assistant were very accomodating, even though we arrived later than planned - her assistant was waiting for us anyway, and gave us great tips about local markets, getting around, etc. The small pool and grassy area were very nice in the August heat, and the A/C worked perfectly. The neighborhood is great, with excellent, modestly priced restaurants.
Travelers tip: take the train/subway from the airport to the trastevere stop, and then take a cab to the apartment -- the streets are a maze in the neighborhood, so it will take 1-2 days for you to navigate.
All in all, it was a very pleasant place to stay, in a very nice neighborhood, where the people were much friendlier, etc., than we have experienced in Firenze or in Umbria. The cost of restaurant food also was considerably less than in Tuscany/Umbria.