This was a wonderful place to stay for our trip to Madrid!
We travelled with three families of people (10 people total) including a baby. Mateo was very responsive to all of our questions and especially helpful with our setup for the baby. We requested early check-in and he arranged for someone to meet us early with keys and explain all the amenities of the house. When a question came up during the stay about trouble with the front door, they were both immediately responsive and had everything fixed for us within a day (even considering it was an issue from the building, not just our apartment).
The space is central to the city, easily walkable to all of the sites between the Palacio Real and Parque Buen Retiro, but still quiet and clean. Each room has its own bathroom which was a great amenity with a large group! We would recommend this rental 100%!