The apartment is functional and it is very well located. The neighbourhood is nice and you can visit Madrid very easily from there (either by walking or in public transportation). The host team is very reactive and help full, (they solve a problem we had with a fan right away in the middle of the night). Also instructions to get there and enter into the apartment were super clear and it easy to follow.
Important to take into account that the apartment is on a very lively street and very close to the Gran via (ambulances, police cars, and people all night long) so it is very noisy when the windows are open. It also have full sun exposition the whole afternoon in summer time without an AC which makes very difficult to have a good sleep at night, you have to choose between the heat and the street noise.