Location, location, location!
This apartment is probably in the best location you can get in Madrid. Right at the center, yet a quiet and authentic Madrid street. Everything is walking distance. You can choose to walk to the more touristic areas such as Callao, Grand Via, Sol, and Plaza Mayor, or wonder through the small streets of Madrid towards Alonso Martinez.
The host was always responsive and flexible when we had to check in earlier to store out luggage.
The apartment is huge. It is literally 5 bedrooms, each with its own shower and small kitchen. Every room has its own heating unit (and I guess cooling in the summer). There is also one big living room with great view to the street. And a small joined kitchen.
This house is perfect for a group of friends or couples.
Great stay, in a great place!