The apartment is located in Chamberi district close to metro line 3 - great for experiencing Madrid. The quarter offers restaurants, bars and supermarkets to shop.
The flat has everything you need and Olivia is a very helpful and nice host. The room is nicely decorated and has an AC which is especially great for warm days. Some people might find the room a bit too small, especially when traveling as a couple / with luggage.
The place is quiet and well connected. Check-in and check-out went very smoothly. I'd definitely recommend Olivia's place for when looking for a place to stay in Madrid.