The Arianda's Art apartment in Lavapiés is very nice and clean. This place is close to everything. During our 3 days trip to Madrid we used metro only twice (first time from the airport). The Museo Reina Sofia or Atocha train station are 5 minutes' walk. Retiro park is near too. Lavapiés is a multicultural neighbourhood with plenty of restaurants, bars, cinemas and theaters. There is a night live near still the apartment is very quiet. You don't hear any noise from the street.
Ariadna and Reymer took care of us. We were welcomed by a glass of wine and we got a lot of tips for places to visit. We would definitely stay there again!