We were welcomed by Kristian's girlfriend, who was really nice and showed us around the place and the maps for central Madrid.
She was happy to help us when we needed advice because I had hurt my leg two days before and therefore was wondering about doctors in Madrid.
The place was nice, even if we were a bit surprised because it is pretty dark everywhere except the bedroom : the living room and kitchen all have windows on a very high interior court so there's not much light passing through, which is a bit sad when the weather is really great outside !
Also, I would not recommend this place for people with trouble going up stairs because to get to the escalator, you first need to walk a flight of stairs, and another one when you get out of the escalator. Also, we stayed there 3 days and it was out of order for two days for no reason (which often seems to be the case). But if you don't mind stairs it's only 4 floors :)
Also, the walls are pretty thin so we could often hear the neighbors, even if they were not being particularly noisy.