The apartment is in a good neighborhood, a bit away from the main tourist attractions. There is a late night shop across the street as well as supermarkets a walking distance from the apartment. There is good public transportation nearby. The interior is nice and welcoming and there is very nice view from the windows. The host who let us into the apartment (Ivan) was very nice and helpful.
Word of warning for people who are sensitive to NOISE: the windows aren't insulating sound at all, which means you can hear the street the entire time including in the bedroom. You can also hear the neighbors through the walls and ceiling some of the time. For us this wasn't a huge deal since we were out most of the time and used the apartment mainly for sleeping, however on some days (especially in the weekend) we would have stupid people standing in the street downstairs, shouting and laughing loudly while we were trying to sleep.
That said, Barcelona isn't a very quiet city in general so I am not sure how this place is comparing to others.