We strongly recommend Ricard's flat in Gracia. It's comfy, fully equipped and lovely. Having breakfast and dinner on the terrace is priceless!!
The flat is close to all amenities, five mins distance from Diagonal tube (two stops to city center) and Gracia area is very cool, safe, ideal for shopping at local art-crafts/fashion shops, it hosts diverse range of restaurants and pubs.
Ricard was very helpful and kind providing all sort of information during our stay and allowing a later check out.
We'll hopefully go back there soon!