The apartment is located in a fantastic and safe area and was well equipped and spacious enough for our group of 6. The area is filled with bars and restaurants and very close to many of the tourist sites. Mattia was an exceptional host, always responding in roughly 30 minutes and very attentive to our needs. The apartment was clean and I would stay there again.
The only minor issue was the lack of hot water after 1 shower, which meant our group had to plan accordingly and take quick showers (but our friends had the same issue in their apartment, so might be a Madrid phenomenon).