Carlo was a great host. He welcomed us at our arrival, was very fast at communication to help us get there, and very helpful overall. He speaks perfect English.
The apartment is great, as described. I fully recommend staying here.
Some people in other reviews complained about smell in the bathroom. We didn't experience this (or maybe just one very minor time) ; this is due to a pump pushing used waters upwards. Carlo mentioned that this will be replaced as soon as building permit is authorized but unfortunately it takes some time to get there. There is a loud noise when the pump activates but it didn't bother me at all because the pump only turns on when there is water flowing in the apartment (which doesn't happen when everyone's asleep).
So that said, I totally recommend the experience. A/C is great after a long visit of Rome in the heat, location is fantastic and I'm glad I stayed at this apartment.