Carlos' apartment is perfect for Madrid - a great location with fantastic amenities, cordial communication, and a beautiful terrace to start or end the day drinking coffee/wine and taking in the sunrise/sunset.
When we arrived he took the time (10-15 minutes) to walk us through the apartment and describe how to use the washing machine, shower, air conditioning, lights, netflix/TV, etc. He was incredibly kind and answered any questions we had. Our only regret was that we weren't able to stay longer.
Highly recommended for a long or short stay in Madrid.