My wife and I recently stayed at the flat for 4 days with my senior-aged parents. We all absolutely loved it.
The unit was very comfortable, plenty of room for 4 with the bedrooms on opposite sides of the flat, which was nice for privacy and a bit of separation.
It's a very well-designed space and centrally located to plenty of restaurants, cafes, and bars. For anything further, it's a quick taxi ride away.
A few things to note: there's a washer AND dryer combo unit in the flat, which was incredibly useful. AC units in the living room and both bedrooms keep each room cool independently, and the kitchen was fully equipped if you need a meal at home.
We're also staying here on our return to Madrid in a few weeks and are very much looking forward to visiting again.