David is a great host. He has all the information you need about Madrid if you are a first-time visitor, and allows you to be free if you have experience in the city.
The apartment is located in a friendly neighborhood that covers all your supermarket, restaurant, bar, public transportation needs. It is located virtually on top of the Delicias metro station, in front of Cercanias and it is a 10-minute walk from Atocha train station. The apartment is nice and the AC works fine to survive Madrid's hot summers.
The bathroom is a bit too small.
The only problem, and David warns you appropriately in his add, are the building's stairs. Be ready to climb 122 steps once or twice a day. Sometimes it feels as too much! NOT recommended for an elderly person.