We spent four nights in this apartment while visiting Barcelona. The location is really amazing, a block from the Metro on La Rambla and right in the heart of the Gothic Quarter. We were able to easily walk to various destinations in the neighborhood, or hop of the subway to get to further locations like Park Güell.
The apartment is very comfortable and attractive. The air conditioning was nice with the hot and humid weather during out visit. We didn't use the small kitchen other than to stash a few bottles of water in the fridge as there were so many good restaurants nearby. The shower in the bathroom was very comfortable.
We had a miscommunication with the hosts about our arrival time but it was graciously sorted out. I'd recommend not waiting like I did until the morning of your arrival to confirm your check-in time. :)
I would very happily stay in this apartment again on a future trip.