We stayed in Gius' apartment for 4 days. The location is perfect to go anywhere in the city and the house offers a beautiful view on Madrid both on the first and the second floor.
Unfortunately we have quite a few remarks about our experience. Firstly, it is impossible to get a decent rest on the first floor as there are no curtains, thus you will be waking up in the very early morning unless you have no problem sleeping with sunlight. Secondly, the sheets for the sofa bed appeared to have a few stains and holes on them. Further, we discovered during the first day that the apartment door had not been locked (you usually access the premises through the elevator directly, so you would not notice it).
The apartment guide talked about an hairdryer, but none of us was able to find it anywhere in the toilet (where it was supposed to be).
The terrace is completely exposed to sunlight which can be very intense during summertime in Madrid. A suggestion would be to add an umbrella and create some shadow.
Also, a proper door to the bathroom would be better to give enough privacy to the people using it.