I truly enjoyed my stay at Jose and Maria's place. My only complaint was that when I arrived, the key was not where they had said it would be.
After messaging them, they were quick to respond and sort out the issue- turns out the cleaning lady had not shown up when expected. While I had to wait 2-3 hours for this issue to get resolved, they recommended a good coffee shop down the street.
As I had no access to my account for a couple of weeks, I am in part to blame for the issue with the apartment's preparations in not responding to their messages about my schedule- however I showed up in the mid-afternoon.
Aside from this small issue in the beginning (which I do not attribute to the hosts), I had an excellent stay in Madrid. The air conditioning was incredibly useful in the heat of the day, and the room was charming. It is about a five minute walk from a metro station, and an easy (and pleasant) 25 minute walk to the Plaza Mayor.
I spent mornings walking through nearby Retiro Park, and at the Prado right around the corner.
All in all, a lovely stay. A friend studying abroad in Madrid stopped by and said the neighborhood was an excellent one in the city.