This place is a MUST stay for your trip to Madrid.
House - Best location. In the heart of Madrid. Everything is around you, just need to step out. Restaurants, grocery store, sights, shopping, you name it, it's close by.
Amenities - Best heating and hot water for this winter months we have come across in our 1 month trip around Europe. Hot water for shower was very consistent and the best one I experienced in Europe so far. They have washer and a dryer (which is very hard to come by), which was a lifesaver.
Little touches - They had bread, muffins, milk, coffee, and tea all ready to welcome us and make it very easy for us to enjoy the city and not worry about early morning breakfast hunt.
Basically, forget the hotel and just come and enjoy Robert and Sylvia's hospitality. We were received by one of their friend, but Sylvia called us personally to make sure we settled in properly.
You guys rock and I'm definitely booking your place every time I plan a trip to Madrid.