The apartment was exactly like the pictures. Very nice, clean, with lots of space. The shower was tiny, but nothing to worry about. The windows open to the neighbours, so not that much privacy. Second floor with a working lift.
Wi-fi connection was good, but reception was terrible. TV was old, so no streamings.
Location-wise, it's amazing. In the heart of Madrid, it's just a few blocks away from Sol, and amazing restaurants nearby. To top it all off, it's in a small-ish street in the back of the building, so no noise from outside.
The check-in consists of grabbing a key from a different location. It's close to the apartment, but it still proved to be a little hassle with luggage. Be sure to prepare for this.
Ramón was very nice and kind. He may take a while to answer, but he eventually does and is so helpful.
Definitely recommend the place!