If Rafa's apartment is available, then just book it!
We had a very good stay at this place. The house is small, but the space has been used in a very thoughtful way to provide all the usual comforts.
We were three people and spent a comfortable few nights in Madrid. Although it was very hot in Madrid, the house itself is rather cool.
Finally, Rafa is a responsible and sincere host. He communicated very clearly before arrival and replied to any questions during our stay.