The apartment is perfectly located in the center of tourist Madrid. It's possible to walk to the Plaza Mayor and Royal Palace in one direction, and the Prado in the other, and it's five minutes from a large Metro + Circania station at Puerta del Sol. A Carrefour express sits 20 meters down the street for groceries, and the neighborhood is full restaurants, bodegas, etc. The apartment is also modern, well-equipped, pleasant and spacious, with two very private bedrooms, 2.5 bathrooms, and a large sitting area. We have stayed in perhaps 20 Airbnb places, and this is the first one with an electric citrus juice squeezer. So if you get tired of tourist Sangria (which seems to be red wine + Sprite) and want to make your own with real fresh orange juice, it's easy to do.
It's on the fourth (top) floor with no elevator, so if you travel heavy (like us) you will get a workout carrying your stuff up. But the payoff is that the top floor is bright and quiet even when the street is noisy down below. Carlos is a very friendly and helpful host, and the Minty Stay agency that manages the place is easy to reach and responsive if you have any problem. We enjoyed our stay very much and would highly recommend the apartment.