The place is very spacious and as pretty as the pictures suggest. Location is on point as it takes less than a 10 minute walk to get to Reina Sofía, Plaza Mayor, Plaza del Sol, Retiro Park, Atocha train station... It's hosted by an agency that is very responsive and accommodating. The whole apartment has an air conditioning system which is indispensable in the summer. Kitchen is well equipped, you can easily do laundry too.
The only minor flaw is the elevator doesn't take you directly to the apartment but a half floor higher so we still had to carry our stroller every time.
All in all, we were very happy here and would recommend this place as a great base from which to explore all of Madrid.