We had a lovely stay in Rome in Alessandra's. The apartment is not far from the center, just a 25 min walk. Also, public transport works very well, and it is fast and easy.
Alessandra wait for us as we were late because of delay on the flight, and also told us the basics for the first day. She was very helpful on every question we had.
About the apartment, it is in a old and classic building. We had to move to another apartment she owns, nothing to worry about as we adapt to almost everything, but it was in the basement of the building (with what that entails) not bad at all but I'm not sure to recommend it for a long term stay
Anyway, we expend most of the time walking and visiting all what Rome has to offer, and stay there just to rest and sleep