We spent one month in this apartment and everything worked out very well. We didn’t have any issues and could enjoy our stay in Barcelona in a very good location! However I wouldn’t recommend the apartment if you are sensitive to noise since you could hear a lot of noise when someone passed outside the apartment, both on the street and from the stairs in the house. Also, the door to the toilet wasn’t a real door so it wasn’t very private.
In conclusion it was a very good stay and the air conditioner worked well! The location is great since it’s in the center and not far from the beach.