I did't meet Sergi, because another person introduced me the flat, but the communication with him was easy. The location is perfect: lots of bars, restaurants, shops, and beautiful sights. The apartment is very nice, clean and Wifi available; maybe it's quite small for 4 people.
Two drawbacks: the temperature of the shower (problem with the warm water supply, impossible to solve during the weekend), and the noise from the bars in the street at night.