Marta's place is located very close to the Prado and the other Art Museums. An easy walk. Lots of small, affordable restaurants, as well. It took 15 minutes to walk to the Royal Palace, so everything is walkable. The apartment itself has much more than a suite at a hotel.
The second bedroom doesn't have a door, just a screen.
That limits the privacy of those in the room, but it was fine for us (two parents and 18 old daughter). We didn't cook but there is a full kitchen. Marta's communication was great and we would stay there again.