It was a perfect trip!
About Gianluca: actually, we've never met each other, but the check-in was perfectly easy - he sent his friend Pietro to meet us. He was very kind and friendly.
About the location: it's just perfect. It's 15 minutes walk to Rambla or the sea, a few minutes to Placa Espanya, Font Magic, MNAC and Monjuic, and literally a few steps to Poble Sec metro station. There are a lot of supermarkets near the flat, including some 24/7, and a big one just in front of the door across the street.
About the apartment: it's clean and very well decorated with posters, figures, books, souvenirs, etc. It's a little bit old-fashioned, but it adds some charm to the overall experience. You feel yourself like at home, not in a characterless hotel room.
Overall: Perfect, just perfect! Thank you Gianluca!