The flat is small but has everything you need. The neighbourhood is authentic, there was a nice bar right down the flat, and plenty of grocery stores, one of which is open 24/7.
Location is great too, you can walk to many monuments (palacio real, plaza mayor, puerta del sol) in less than 30 min, there is also a metro station down the street. Ana was reactive, and check-in experience was very smooth. Overall, a very good experience, would recommend it.