Very nice appartement in lovely neighborhood, very central with many sights in walking distance. We used the local market (Marcat de Santa Caterina) for most of the daily shopping needs.
We enjoyed the terrace in the morning sun and the apartment was very nice inside. We used some of the recommendations for restaurants ect. locally these where all very good.
We recommend to buy tickets in advance for the more popular sights like Gaudi buildings, Picasso Museum, La Sagrada Familia so you can avoid the long waiting lines.
If you buy a Barcelona card make sure to plan in advance how to spend the days you have the card, otherwise we think it is to expensive.