​This apartment was relatively okay in relation to other Airbnbs I have stayed at in Madrid.​ The positives were that it was clean and well-managed, in a fantastic location, and very easy to access. Flavia was very personable, responded very quickly on Whatsapp, and was great company. Everything was in working order, there were plenty of pots, pans, and cups, and from a functional perspective, I would give this 5 stars.
With that said, there are a few things I would note, as I've listed below. I booked this residence to accommodate my family attending my wedding in Spain, so functionality was not the only thing at stake.
1) The term "luxurious" in the title had a lot to do with my booking this residence, and found myself quite underwhelmed from this aspect. I would not call this apartment "luxurious" by any means. The lighting in each room and common area was very poor and underlit. The furniture was subpar in terms of quality, and it resembled more of a roughed-in apartment. Perhaps an appropriate term would be "cozy"... but not luxurious.
2) Flavia's entrance to her own apartment requires her to come into this Airbnb via the front door. This was an area of concern to my family, who did not like this arrangement for security purposes. It also qualifies this Airbnb to be a shared space, rather than a separate-entrance home. So from that perspective -- if I had known this would be the case, I would not have booked this residence.
3) There is a fine for lost keys which I wasn't made aware of on the first day. This created a little bit of panic on the last day, when Flavia decided to charge 20 euros per lost key replacement, very close to check-out time. Of course, the keys shouldn't have been lost to begin with, but knowing it on day 1 would have allowed me to brief my family to be extra careful because there is a fine. Just a small headache amplified by the fact that we only knew about this "policy" at the last possible minute.
So those 3 points definitely affected my rating, but all in all, if you are okay with the caveats I mentioned, Flavia is a great host and this location is hard to beat.