First the good: the place is beautiful and pretty much brand new. So new that I don't think the host really new how to use the brand new A/C cooling system.
The bad: it's hot in Madrid and when we checked in it was 105 degrees inside the apartment. The cooling is in the cement floor and either didn't work or takes forever to cool the apartment. After 4 hours, it hadn't cooled the air at all so we stayed the night in a hotel (Alicia was very helpful and apologetic and refunded us that night). But it still was not cool the next morning so we had to cancel the stay. Alicia refunded us and did the right thing, but they really should have either pre-cooled the apartment (if it takes a day to do so) or not advertised it as having AC.
But if the AC thing gets sorted out, I'd highly recommend the place. Like I said, it's clean, roomy, beautifully designed, and really centrally located.