I stayed in Maria's apartment for two weeks, and was extremely happy. It is comfortable, light-filled, and extremely well outfitted. Maria met me to show me around the place, and was then available throughout my stay if I needed anything. She even rented me her bike for the entire stay, when I mentioned that I was thinking of getting one. The location could not be better -- a very typical Madrid block in the center of Malasaña, which to my mind is the best, liveliest, coolest neighborhood in the city. A great place for a single or a couple; 4 people might be pushing it.