We have only the positive things to say about Gianluca's place. It is located in a very calm neighborhood but very close proximity to public transportation stops (train and bus), also just a short walking distance to Vatican via low traffic streets.
The apartment was spotlessly clean and with good air conditioning, which made the heat bearable especially during nights. Also, the apartment is on the top floor and you can almost never hear any neighbors. I, being a sensitive sleeper, bought a bunch of air plugs but didn't need to use them a single time because everything was so silent at night.
Definitely, one of the very best places to stay in Rome.