If you value centrality, convenience, and comfort then this is the place for you. This apartment is in the heart of a very centrally located area; most things are within walking distance (royal palace, Puerta Del Sol, Plaza Major, etc). There are shops, restaurants, theater, and everything else you might need within a walking distance.
The apartment is cozy and it has what we needed for a 7-night stay. It is on the 3rd floor (4th for U.S. standard) and there is no elevator so be aware of this. By the end of the stay, I felt like we got acclimated to the endless stairs. :)
It is a wonderful apartment and I would stay there again when my travels take me back there.