I'm not sure I understand all the 5* reviews.
The architecture of the house is incredible and it must have one day have been luxurious.
Today though it's looking quite tired. It's very sparsely furnished (you can see this from the photos) but the furniture is often broken and/or cheap. Often IKEA. It feels like at one point the house was emptied of all its original antique furniture and has been replaced with cheap items. Our mattress was old and the bed squeaky. The bathrooms have been remade cheaply several decades ago and the kitchen too.
Xavi is lovely but his welcome tour was rushed and we had to ask him for basic items like shampoo or water as they weren't available on our arrival. We also had to search for an additional blanket as it was cold, and only found an old duvet (and didn't feel the cleanest).
It felt like staying at an old lady's abandoned house rather than at an Airbnb. You can feel the lack of care for the house itself: the front door does not open properly. Broken light switches, broken toilet lid etc. I felt sad for the house. We would save it if I could!
Overall, we didn't see the care from the host that I would have expected for €100/night + service fees. More like a hostel stay in a once grand modernista house.