Our stay at Fernando's apartment was wonderful. Despite our arrival at 9:30pm, Fernando met us at the apartment personally and spent more than 30 minutes going over all of the things he recommended that we do in Madrid. He also marked some of his favorite things on a map. There's no way we were able to do it all so I guess we will have to visit again!
The apartment itself is very nice and was recently completely redone with all new appliances. It was easy to walk from the Atocha train station and is walking distance to Plaza Mayor and many museums and other landmarks. The street is relatively quiet but the larger area has a lot going on and seemed to have a pretty active nightlife. All in all it was a wonderful stay!