My fiance and I loved our stay! Blanca and Maria were very welcoming and always available to answer our questions. The previous guests had broken something and they were able to fix it right away.
As far as the apartment, it was a beautiful space with both a balcony connected to the apartment and an amazing rooftop terrace with views rivaling those of Parc Guell (a 15 minute walk away). It was very clean and has all the necessary amenities, including guidebooks and a fan for cooling down. The metro is less than a 10 minute walk away, and the city center is a quick 10-15 minute metro ride from there. It's in a really nice neighborhood, Gracia, which has many nice restaurants and bars.
It's on a hill which allows for such great views but can be a bit of a drag after a long day. It's totally worth it in the end, though.
I'd definitely recommend this place to anyone looking to stay in Barcelona.