It is absolutely a terrific location. It is on a quiet, pedestrian only road and a block from Madrid's Time Square. You can walk to most locations although it is only about 7 euros to take the cab to the Museum Prado.
The entire apartment has been fully renovated and is run professionally. The beds are comfortable and the modern bath rooms are spotless. Ani, who greeted us, spent all the time necessary for us to understand the apartment. She even made sure we could connect our electronic devices to the apartment's internet. The only caveat is the fact that the apartment is on the 3rd floor and there is no lift. Highly recommend.