The apartments are great, the staff really helpful and the location perfect for Madrid centre.
A few comments, I was there 2 months and the apartment was never cleaned once. I had to clean the bathrooms myself despite being under the impression that there would be some cleaning.
It is also noisy in the building. Because of the design of the building when people come in they can be heard through the whole building and even the front door banging closed. I was on the third floor and I could hear it.
It means that I was disturbed a lot during the night as people came home from nights out.
Perhaps my fault because I prefer open windows to air conditioning.
Otherwise the apartments are excellent. Great location for central Madrid. Modern and decent size though i wouldn't recommend for more than 2-3 people.
Madrid is really hot and with 3 people in the apartment it could feel crowded and hot.