What an amazing apartment, if I will go back to Madrid... I know where I'll stay! The apartment has the perfect location and is close to everything (we walked everywhere) though it's not noisy on the street. The facilities are great and the place is very inspiring with the lovely bookshelves covering almost every wall in the apartment. We worked there for 3 weeks and the wifi was great and strong (though sometimes when we both had video calls it was sometimes (not always) a bit tricky). It really felt like home in this wonderful city.
The host, Javier, was amazing and I couldn't have wished for a better one. The apartment was clean and had a dishwasher and washing machine. I would 200% recommend this location to anyone.