My husband and I stayed in this apartment for 4 nights. We loved the location; it is in a dynamic and diverse neighborhood of Madrid. It's central, walkable, and close to a supermarket, restaurants/bars, train station, and great views at the top of the hill.
As mentioned in a few other reviews, we struggled with the check-in. No one met us at the apartment, and we got confused by the lock boxes for the door key, and the door to the apartment was a bit of a pain.
The apartment is super clean and beautifully designed, but we felt that it was a bit smaller and darker than portrayed in the photos. The kitchen is super nice; we cooked a lot of our own meals. We used the pull-out sofa bed, stove top, dishwasher, and washing machine, which were wonderful to have! We did have to message the owner about a broken toaster and how to take out the trash, but they were responsive and helpful.
We loved the rain shower and double vanity, but found that two people taking back-to-back showers resulted in the second person running out of hot water. We fixed this by having one person shower in the morning and the other at night.
We did note that the walls were super thin and could clearly hear our neighbors, but this didn't cause us any issues with sleeping.