I didn't meet Massimo in person, but I spoke with him on the phone, and his email communication was very helpful and pleasant enough.
I had a great time in his apartment. It's as advertised, immediately next to the Trevi Fountain. It's a very busy spot, but at night it is calm and peaceful, so I had no trouble sleeping.
The apartment itself is small, and the kitchen is basic with no oven or washing machine. But that suited me anyway I was eating out and certainly had no intention of washing my clothes whilst on holiday! The bed was very comfortable with a high quality of bedding. There is an air cooler/heater if needed.
On arrival at the hotel where I was to pick up my key, they gave me the wrong key. But I called Massimo and he sorted it straight away, which was appreciated.
I would recommend this apartment to somebody who doesn't mind it being small, with a basic kitchen.