Stayed here with my wife and two kids and we had a great time at the location. It is right off of Plaza Santa Ana which proves a central location for all the major museums, the Plaza and the Palace which makes for a great stay in Madrid.
The place was very clean and nice and the beds were comfortable. The front room looks out over a street with a couple of restaurants which we were warned could be loud at night, but we weren't bothered in spite of large crowds at those places. The room is well insulated from the sound if the window and shutter is closed.
Rafael was a great host and he provided a nice booklet with lots of tips on the area shops, restaurants and sites.
Was a little more pricey than some of the other options, but worth the expense for the location and quality apartment.