We stayed a month in January; perfect location and away from touristy areas, 100% walkable and safe; the place is on Rambla Poblenou with Bogatell Beach 2 blocks away and almost any necessity supermarkets, groceries, shopping, restaurants, bakery, pharmacy, home goods, etc) at your fingertips; no car needed but parking is available; bus and metro easily accessible. My parents joined us for 10 days and it was comfortable for 4 people, and private as they had their own bedroom/bathroom; the main bedroom has an ensuite. Kitchen well stocked for cooking. Balcony was great for a.m. coffee or p.m. wine! One minor thing: while there is generous closet space, there aren't any dressers to store folded clothes so we hung up what we could and worked out of suitcases for everything else.
The building and the apartment were spotless. Flor and Nat were amazingly helpful and responsive; we had an issue with the heat but they mobilized immediately to help. I will return!