I would definitively recommend Monicas Appartment! The location is 10 minutes from Rome Termini (main train station) and almost anything you might wanna visit in your time in Rome is reachable by foot. Also there are many restaurants and excellent cafe right across the street. Her mother (who lives one door next) was also always available for us and provided us with some juice and croissant. One minor thing, if you plan on staying in the room at daytime, unfortunately, the room doesnt get much daylight, so it can get quite dark.
Mile grazie!