Overall I would rate the stay in the apartment as very good and would definitively book the apartment again next time I come to a Barcelona with a group like this. Gio is a very nice and friendly host, answered very quickly to my requests and was also flexible with regards to check-in time and when I had to adjust the number of guests 2 days before arrival.
The apartment itself is quite alright and in a very nice area (relatively central). There were enough towels and blankets and also the kitchen was equipped nicely. Really the only things I would note that was not 100% perfect is that the A/C is located in the living room and does not sufficiently cool down the entire apartment. Even with open doors the sleeping rooms stay relatively hot. Other than that everything was perfect and we had a great stay!