We had a short stay here, but it was lovely. The apartment was clean and spacious, with modern decor touches. The check in process after hours went smoothly as we were sent very detailed instructions beforehand on how to enter, and registering the next morning was quick, and allowed us to get recommendations from the concierge. There are some nice touches, including water waiting for you and a bathroom amenity kit. We accidentally overdid it on the AC, so could have used an additional blanket, and couldn't find utensils (the kitchen was otherwise fully stocked, including dishwasher soap), but I'm sure these would have been furnished if we had asked for them.
The apartment is set in a central location, just a few minutes walk from Las Setas, amazing cafes and restaurants, and a 30-minute walk from Plaza España and other sights like the cathedral, and the Alcazar. In spite of being in a popular area it was very quiet at night, and felt very safe both in the apartment and walking in the area. We would definitely stay again!