Matteo was very responsive before and during our stay and sent me information about the city before my arrival. The very friendly housekeeper greeted us when we arrived and although she didn't speak any English and we didn't speak any Italian, we were able to communicate well with rudimentary terms and signs. We met up with Matteo and his family later, and he was very eager to show us the fantastic view from the upstairs terrace and pointed out all the important landmarks and provided advice on what to see and where to eat. Matteo and his family were very hospitable.
The location of the apartment was fantastic for us as we were able to walk everywhere we wanted- to the train station in 18 minutes, to the best pizza places within 5-8 minutes, to the museums within 20 minutes, a supermarket 5 minutes away, etc. Also, if you're looking to pick-up souvenirs, the shopping area for that is very close by. An added plus is that there is a taxi stand right outside the apartment, which was very convenient for catching a ride to the train station or anywhere.
The apartment is much more spacious than it seems in the pictures. There was plenty of hot water in the shower, A/Cs worked great (although we didn't need them much at the end of September), beds and sheets were comfortable, and washing detergent was provided which was much appreciated for doing laundry. Washing machine worked great and did not take 3 hours as one past review mentioned. It took the standard time for a load- about 90 minutes or less. There was a large drying rack too, and the clothes dried indoors overnight. Although Naples is not the safest of cities, we felt very safe on the 4th floor (with elevator!) with several doors, gates and locks between us and the street.