It was very nice staying at the Airbn!. We really appreciated the location, washer *and* dryer, elevator, and style (lighting and colors). (The elevator is large enough for about 2 people and some grocery bags. Not for like a wheelchair or anything like that - FYI. I think that's the norm.) There is at least 1 grocery store nearby - which was very handy, subways and buses, and cafes. The Sagrada Familia was beautiful (like 1.5 blocks away). At night between 10-12, the tower with the star lights up so we took a stroll at night to see that - other tourists still out then and plenty of street lighting at the Sagrada. At least 2 of the Hop on Hop off tour bus routes goes by the Sagrada Familia - so you could start that in the morning and go back to the Airbnb area when you are ready.
We took taxis to and from the Sants train station, Airbnb, and airport. We used the Cabify app (recommended by the host) to request a taxi ahead of time to leave the Airbnb at 4 am so we could catch our flight. A driver was assigned, and we got to the airport on time.
Only 1 set of keys to the building, elevator, and unit. The door automatically locks behind you so be careful to always have the keys on you. Door lock is a bit tricky, but I think that's the norm - had same experience with the door lock at our Madrid Airbnb.
The suggestions would be for the dishes and silverware to be cleaned more often. There was food on the silverware so we cleaned a set of dishes before we used them, then kept using/cleaning those same dishes. Also, every hotel and Airbnb should wash the bedding between users, but they don't. There are always hairs at each place.
They probably don't have control over this, but I suggested to the hosts (via the Airbnb review) to ask the building operator to somehow ventilate the stairwell area. As someone with asthma, it bothered my system going in and out. Plus, stale air can carry germs.
We enjoyed our stay, and the apartment is very cozy and home-like! I could see staying again if we are ever in the area or recommending it to friends!!!
(Side note: it's summer of 2022 and flying from the US to Spain and back was terrible. American Airlines and Iberian Airlines lost our checked bag, and 2 weeks later we still don't have it because they are ping-ponging us back and forth. You have to go through exhausting security checks at every single airport along the way. The airlines are overbooking and trying to process more people than they can actually handle. So while staying in Barcelona was positive, the experience of flying to and from the US was extremely negative. Especially at Chicago O'Hare and London Heathrow.)