Amazing AirB&B! The best we've ever stayed in. Luis is a wonderful host! The kitchen is huge, and has every appliance you could need (including a washer/dryer). Very nice bathroom with a spacious shower, and such a comfortable king sized bed. The pictures of the place are very accurate.
Only (small) downside with the apartment is that the bedroom wasn't very sound-proof. However, that might be the case throughout Madrid. Luckily, the neighbors weren't too noisy.
Highly recommend that you stay here!