Diego is a nice guy and the apartment is located very close to major sights, such as the Madrid Rio Park, Palacio Real and the Almudena Cathedral ("close" by Madrid standarts of course, since it's a huge city).
It was however a very mixed experience. While enjoying the good location, the cleanliness of the apartment could have been better. The most disturbing factor however was the constant and high level of noise, to which the host contributed strongly by having loud phone calls and watching TV in a high volume.
It is an ok accomodation for a short stay.