2 words: best location. The apartment just across Sagrada Familia. So your view from the balcony is Sagrada Família :)
Another plus: there’s a reception so if you arrive before the check in time, you can drop your luggage first and they will bring it up once the place is ready.
One thing to note: the apartment was in 5th floor with no elevator. So expect a lot of exercise while staying there 😁