As most of the other reviews stated, the best part of this Airbnb is the amazing view of the Royal Palace from the south side of the apartment. It's also located right on Gran Via next to the Santo Domingo Metro station, so very convenient to most places in Central Madrid. The Jacuzzi is a nice touch.
Now to the caveats. The apartment has 2 bathrooms, but they are literally the 2 smallest bathrooms I have ever been in my life. We are not big people, and it was definitely claustrophobic for us. The check-in/check-out process was also not ideal because Pablo was not available so we had to contact his assistant (who was actually the maid) for both check-in and check-out, and she spoke zero English. I tried my best to communicate with her in Spanish but it was extremely difficult to understand her. The furnishings of the apartment are also quite dated, likely due to lot so use from many Airbnb guests.
Overall, decent stay, but definitely one of the least comfortable that we've stayed in. A+ for location, C- for communication and claustrophobic bathrooms.