The apartment has an incredible location that places it near the Retiro, multiple metro lines, and tons of great restaurants and shops. The unit is small but works well for one person even for a longer stay. It can also accommodate two people pretty comfortably, but I wouldn't recommend it for more people--especially for a longer stay. The building is very nice, and everything was very clean. The air-conditioning also worked well, which I appreciated during a summer heat wave, and the unit was extremely quiet.
Finally, Luisa is a great host. She made checking in and out extremely easy, and she communicated very well before and during my stay. I would definitely book with her again.