The location is perfect, we could reach everything by foot and little Supermarkets and nice Cafés and Restaurants are also nearby.
The room was as described and visible on the pictures. Pretty small but enough if you only want to sleep there. You can also rest in the living room, which has a nice view.
The missing window in the room was no problem, as the room had Airconditioning. One has to be aware that there are also more rooms in this flat and the neighbours can be loud sometimes. The walls are thin and you can hear talking in normal volume.
We didn't use the kitchen, but everything you need is in there.
The contact with Mario worked perfectly, he always responded directly.
Would recommend this place for people who need a place to sleep in the centre. Will definitely come again when in Madrid :-)