This is an excellent place to stay in Madrid, especially if you are arriving or departing from Atocha station - it's within easy walking distance of the station, which also connects to the Metro. In addition, you are close to a supermarket, the famous Retiro park, and not far from the Prado and other galleries. More importantly for some, this appears to be a quiet neighbourhood, which seems to be quite rare in Madrid.
The apartment is compact (as shown in the accurate photos), especially the kitchen area, so if you plan to do a lot of cooking this might be a challenge (and I did not find the induction stove top intuitive to use). The best aspect of the apartment is the very large terrace, a bit too cold to enjoy while I was there, but it provides the opportunity to stretch ones legs and get fresh air without leaving the apartment (very helpful if you're there during the Coronavirus lockdown!).
The windows are double-glazed and the heating came on automatically and worked well, so I would recommend the apartment for winter visits as well as in the summer when air-conditioning is provided. I would be happy to return here for my next visit to Madrid.