Carlos apartment is fine. It has everything you need. It's really great located,so you can reach everything by foot. Only thing that we didn't like is a lack of daylight, since the window in the living room is so small, and in strange position (right corner of the room) and you can open only half of it,so it can be little claustrophobic. You should have that in mind if you're planning to spend more time at the apartment.For us it wasn't a big issue, since we were ther only for sleeping. Anyway,I would recomend Carlos apartment if you planning visiting Barcelona.