I place my stay at Paz's penthouse among the best Airbnb's (and I have stayed at a lot!). Her co-host, Cecilia, made check-in a breeze and helped me with anything I could possibly need.
The very private penthouse is located in a historic building in the very lively Lastarria neighborhood, which is packed with good restaurants and interesting shops.
The apartment itself is spectacular and very stylish, I would stay here forever if I could! First, the furniture, mattress, and other finishings like the bathtub are high-end and very nicely maintained. I've stayed in lots of generic, sterile Airbnb's with IKEA furniture--this is a complete departure!! There are also several beautiful plants in the apartment. Second, there are some extremely nice additional amenities, such as a combined washer/dryer, a tank with filtered water (Santiago's water has a very high mineral content and does not taste very good), and a fully equipped kitchen.
Perhaps the star of the apartment is the outdoor patio, which has lots of shade, privacy, and comfortable lounge furniture.
NB: if you are a musician or love music, you will be especially at home here. There are instruments, like a piano, guitar, and cajón, and an ipod (and sound system) full of fantastic music!