The apartment itself is in an unbeatable location in Madrid. I visited with my parents - they took the bedroom and I took the super comfy couch bed! We all slept great. The beds were comfy, the apartment was super clean and very quiet even with bars all around the neighborhood. Javier also kept the apartment at a nice temperature which was a nice relief from Madrid's summer temperatures.
Javier was amazingly kind and made sure we had everything we needed during our 3-night stay and gave great advice for what to do and what to eat in the area. My parents and I slept early but Javier was super quiet and we were never bothered by noise at all.
If you are traveling in Madrid, I highly recommend this apartment!