We had a nice stay for 5 people for the night. The location is incredibly convenient for La Sagrada Família, which is wonderful to walk by at all times of day and night and view the differences, and relatively easy to get to/from the train station and airport.
Thought kitchen was particularly large for Europe, so good if your group will be spending time cooking/eating at the flat. Nice amenities and can be cooled off quickly with opening the windows, though you will get a bit of street noise. Marisa and her son were very helpful with check in and providing recommendations as well!