Irene and Ciri's apartment is newly redesigned, very modern and tastefully decorated. Everything you need is provided. They are also very responsive and helpful. The apartment is a 5 minute walk to Lavapies metro station, where there is also a supermarket open 24h. Many sights are within walking distance, such as Plaza Major, the Reina Sofia and Thyssen museums, and even the Prado.
We had a great stay and would definitely come back again next time we visit Madrid. Highly recommended!