We stayed at the apartment 2 nights and we couldn’t ask for better! The apartment is perfectly located near Parque del Retiro (a 5 minute walk).
If you should take the Aerobus you will be very close to the apartament, which was very convenient for us. Subway as also a 5 minute walk away (2 stations).
Sergio was very helpful throughout the entire trip and even let us leave our luggage at the building so we could enjoy the rest of the day before the flight! Thank you very much!