The apartment is just excellent. It is very very spacious. We we're two so it was as big as a palace, but it could easily (!) fit for two couples (4 adults). Giovanna is extremely nice and welcoming, and also very kind. She left us all sorts of snacks in the kitchen, including wine, coffee, and many more.
Location is perfect for the Vatican, and close enough for most of other stuff. The neighborhood is pretty and safe, and Giovanna gave us a few recommendations for food around the apartment.
Our grade wasn't maximal only because during our stay there was a lot of noise in the adjacent apartment, and it interrupted our sleep at night. Other than that we we're very satisfied.