A lovely flat, clean and rather splendid, in a really convenient location. Rome Termini is just a stone's throw away and the Colloseum an easy walk. The immediate area is a bit scruffy but didn't feel threatening.
All communication with Julian was friendly and helpful in advance, and he and his wife remained welcoming despite our ridiculously late arrival (there's a fee for night-time arrival which is explained in the house info).
We would definitely recommend this place for a stay in Rome - we were four, two adults and two teens, but there are extra beds.