This was a good stay for our few days in Madrid. It's located on a street with THREE nightclubs, but the soundproofing in the apartment is AMAZING. It comes with blackout shades as well so the minute you close the windows and shades, you hear and see nothing. Now, the stairwell on the other hand is different and we heard people coming home anywhere from 3-5am and having long loud conversations but that's nightlife for you. The apartment provides a lot of spaces to sit, a decently sized bathroom, and a super firm bed (which I personally loved the firmness). Scarlat even left us with some treats which were super handy to eat when we left early for our day (tasted delicious too).
2 caveats to consider: 1) the towels and bathroom smelled like cigarette smoke. I didn't feel super clean drying myself off after showers. 2) the internet is very spotty and can be slow depending on where you are, so if you're trying to work/do video calls, this may not be the best place.