The flat was exactly as described and expected. We loved the space - it was huge and well designed, with more than enough space for three of us. The location was also perfect, just a short walk to Plaza de Olavide and to the shops/cafes/bars on Santa Engracia (and only 3 mins walk from the nearest Metro stop at Iglesia!).
Check-in and communication were simple and well-managed. I'd absolutely recommend the flat to others traveling to Madrid, especially larger groups (3-4 people) or families.
Only one potential downside - the wifi is a little spotty in parts of the flat. I had trouble joining zoom calls from the desk space upstairs. But... oh well, you're in Madrid :)