We had a great time in Rome and at Mattia's place. We were 2 in the apartment and it was very nice, we had everything needed and the balcony is very cute. We unfortunately only met Mattia at the end of our stay since he had to be out of town the day of our arrival but communication was very smooth and easy, he also left us a note at the door with some chocolates : )
The apartment is central, close to 2 metro stations and also close to nice restaurants and breakfast spots. Mattia also recommended the best places to eat and sites to visit in Rome which was very nice of him.
We only had one problem with a leak in the bathroom sink but we managed, we told Mattia about it and I am sure it was taken care of.