We stayed in Alvaro's place for 5 nights and we really enjoyed the apartment. The location is great and you can go to most of the known places only by walking. The neighborhood is safe and quiet at night. The room and the bathroom is spacious enough for 2 persons and it was very clean. It also has air-condition in both the living room and bedroom, which was very important for us cause of the high temperatures in Madrid (42 C).
Alvaro is also a great host and very responsive to my messages and our requests. He helped us having a great time during our stay! I can definitely recommend it.