The apartment is fine, although very small, has almost everything you need for a short stay in Madrid. However, the sound insulation is very poor, so be sure to bring earplugs if you want to sleep in peace. Communication with the hosts was good, but my question about a possible earlier check-in remained unanswered, and I didn't like that lack of cooperation. On the other side, the problem about broken hair dryer was solved quickly and they reacted very fast.
The location is perfect, in the city center, minutes away from Gran Via.
All in all, okay apartment for a few days in this beautiful city.