William's apartment is very central, close to the Atocha station, and close to late open restaurants, what was crucial to us. Unfortunately, we couldn't enjoy much the place, as we stayed that for only a few hours, between our late flight and our early train. William was very kind and waited us ultil 1am as we were delayed by a taxi strike that affected all Madrid transport the day we arrived. William could even find time to talk to us about Madrid and Spain. The room was great, very clean and with a good bed. It even has a private bathroom!
The only thing I regret was not having more time to stay there. Highly recommended!