I stayed in this apartment for 5 days with my family. The house is small but perfectly organized, with modern furnishings. It has all the necessary, bed linen and towels, a kitchen with everything you need. We had to do an online check in and to use an app on our phone to open the doors (but we could also use the keys), absolutely functional. The owners were helpful regarding check in and check out times. The icing on the cake was the location. PERFECT. We could reach every main places of the city by foot in 10/15 minutes, and we were only 5 minutes to Puerta del Sol.
Absolutely recommended!!!