Our stay at Luca's place was perfect. The apartment is big in dimensions and modest, in a qualm neighborhood without tourists. Morning coffee in the small balcony overlooking a sunny patio made us feel like locals.
Luca explained how to reach the center's main attractions (10min by tram right next to the apartment) but we preferred to walk as we wanted to discover Trastevere by wndering around its streets.
For a few extra € we checked in at 11pm (the train comes straight from FCO airport to the station in front of the apartment), and Luca was waiting right outside. He even recommended a nearby traditional restaurant that serves great pizza and opens quite late, which is always convenient.
It was 6 of us in total which means 3 of us slept in the two double convertible couches, the mattresses of which were perfectly comfortable.
I would more than gladly go back to Luca's place when visiting Rome again.