The apartment itself was great; very clean and centrally located with a good amount of space.
However the check in process was a nightmare. We got to the apartment at 3:00 ( exact check in time) but were not able to activate our electronic keys until 4:00 after constant texting of the owners. That got us into the building, but when we got to our apartment, we were greeted by the cleaners who said they needed until 5:30 to finish cleaning, a full 2.5 hours after check in was supposed to be.
Other than that, again, the place was very nice and we had no other complaints. We had a great time in Barcelona!