My teenage son and I made a short 4 day trip to Barcelona to visit his older brother who has been studying at Universitat Automuna de Barcelona (UAB) for the spring. Sandra's flat was perfect for us. There are 2 bedrooms with comfortable beds, and a comfortable futon in the living room which my older son used when he stayed with us. His homestay was with a family living near La Sagrada Familia, so it was easy for him to go back and forth as needed.
The location was great, right near the Joanic stop on the metro, so exploring Barcelona was a breeze. And Gracia was a great place to hang out with lots restaurants, bars and cafes. The flat has a nice kitchen and there was a Bon Preu Supermercats right around the corner that had whatever we needed.
And our favorite part of the apartment was the terrace with great views of the hills and neighborhood. The apartment is on the 9th floor so it was a nice vantage point from which to view the city. And the elevator in the building was convenient and in good working order. I would highly recommend Sandra's place and City View Apartments.