We have enjoyed staying at Ignacio's apartment. The location is fantastic, right in the center of the old city and only couple of minutes to the Prado museum, plaza Mayor and plaza Del Sol.
The apartment is in the old building but with a modern bathroom, cosy patio, large rooms `and well equipped kitchen.
Ignacio is a wonderful host, his suggestions for restaurants were fantastic.
To cut it short we recommend Ignacio's apartment to the airbnb community.