We loved Oscar, Paula and Javi's apartment. Javi met us and showed us around the apartment and was very friendly and helped us with any questions. The apartment was supplied with everything we needed, really good air con (perfect for the Summer heat) and a great shower. The location is super central which meant we often went back during the day for a rest. It is no more than a 5 minute walk to the Prado and very close to El Retiro Park. It was located in a quiet, friendly and local neighbourhood, with convenience stores and a supermarket nearby. It was extremely close to the metro which made getting to/from the airport very easy. The apartment is up 3 flights of stairs which was fine for us, but if you have a lot of luggage it's a little bit of a walk.
We would highly recommend Oscar, Paula and Javi's apartment! Thank you so much for such a great apartment, we love Madrid! :)