Central location in Saint Antoni within walking distance to most if not all locations of interest in Barcelona. We had young children and found it very simple to use local taxis to get around. The mytaxi app was very similar to the (not available in Barcelona) Uber app.
The apartment itself was on the 4th floor of a beautiful building with a *charming* elevator, and views onto a large central courtyard. We were 3 adults and 2 young children and had plenty of room for a city apartment. Noise was as to be expected in an old city apartment, but it did not hamper our or our children's sleep.
The apartment was well stocked with the basics, including coffee and a bottle of white wine :) The local neighborhood had a few great restaurants (we ate at Casa Dorita and Mon Viet) and at least one great ice cream shop (Horchateria Sirvent). We looooove Barcelona and would definitely consider a stay here if we visit again!