The apartment is exactly as shown in the pictures: it has a lot of character and it has everything one may need for a 4-5 days stay. Location is really perfect, right in the heart of Malasana, a very nice district with a lot of shops and bars, and the city centre (Plaza Major, Puerta del Sol) is reachable with a 15 minutes walking. Even if the area is pretty lively and noisy all day long, the apartment is super quiet, as it gives on the internal patio of a big building. This is indeed also a minor shortcoming, as there is not so much light coming in. But we did not find this such a problem, as we were spending basically all day outside.
Communication with Daniel was perfect, he was always very fast in answering to all our messages and we did not have any problem in meeting him at our arrival.
I definitely recommend this apartment and I hope I will be back soon in Madrid.