We really enjoyed out time in Rome. Massimo was a great host and the apartment was fantastic - exactly as it looks in the pictures. We booked Lost in Time based on a recommendation, and would definitely recommend it to others.
It was good that Massimo was able to recommended and book a car service to collect us from the airport, which made our first day run smoothly. We also found the information book in the flat really useful, and went to several of the restaurants Massimo recommended (they were very good).
The apartment is in a residential block not far from the porta maggiore. It was clean and well furnished, with a small but well-equipped kitchen - we cooked dinner a couple of times and it had everything we needed. The bedroom in on a mezzanine - a great view but mind your head on the low beams upstairs!
The bus to Termini station runs past the flat (and runs every few minutes), with the tram about 5 minutes away and 15 minutes walk to the Metro. It's also not far (10 mins) to the lively, but not touristy, Pigneto district with lots of bars and restaurants. We used the public transport a lot to explore the sites of Rome and out into Lazio.
In summary - we'd definitely go back!