William and his Bnb are great! William waited for us at home to greet us and show us his place and recommended local place to eat. We took the Express shuttle from the airport to downtown Madrid (5 euro). Then is around 10 mins walk(slightly uphill) to William's Bnb. It is close to everything, super market are just few mins walk away. 10 mins to the Mayor Plaza. We walked to all the sightseeing spots. The private bathroom might be on the smaller size, but is clean and functional.
Definitely recommend William's place!