The photos really don't do the apartment justice. It is perfectly located if you are museum hopping, right in between Museo Reina Sofia and El Prado. Next to the Caixa Forum. Walking distance to the Plaza Mayor (15 minutes).
The apartment itself is clean, comfortable, has nice lighting.. Close to very excellent restaurants.
The included parking was a lifesaver. Diego sent me an email of interesting sights and things to do close to the apartment, which sadly we couldn't do (we only stayed there one full day).
But I would not hesitate to reserve again, highly recommended (especially if you have a car).