This apartment is an all around great choice!
The communication with the hosts is smooth and prompt, they are very helpful. It is located in a residential area of the city, so you get a feel for the local life and culture.
The apartment itself was very clean, well equipped and just like on the photos. We were not disappointed and will be back when visiting Barcelona.
(The only advice I would have is to make sure you pre-register with the company who provides the keys online, as that can be a long and painful process if it has to be done on the spot.)