Location is good, really 10 Minutes Walk to Sagrada Familia, and very close to metro, however for us as couple with baby was still difficult(not all metro stations have lift, and the electric stairs are almost only for going up, not bothways) . Restaurants in the neighbourhood re really helpful, but most of them (or the ones with good reviews) are opened from 8 pm for dinner. I assume this is the spanish standard, however we find it too late for dining...
Communication with David was very good, he answered promptly and waited with the check in (our plane had delay, so it wasn't really our fault plus we had to carry the baby buggy through the metro stations with limited lift)
In our welcome map we were told to be quiet after 10 pm, well the neighbours were first after 2 am quiet. The walls are so thin, could hear the high heels on the stairs and a special smell(marijuana?!) was coming through the window in bathroom.
All in all the appartment was clean and well equipped to cook, for young couples should be perfect, but don't expect 4 * hotel.