The flat itself is spacious and well-equipped, a regular airbnb, the real outstanding point is the rooftop terrasse with a view overlooking the city.
Area is a different kind of BCN vibe: scenery is great, it's right next to a former anti-aircraft bunker from the civil war, where people go for drinks and chilling (u gotta bring ur own stuff), enjoying the panoramic view. There are two wonderful parks around, and the area doesn't have that kind of touristic-hub feel that you get in the center (although Park Guel is really close, but you just don't notice it). There's also a nice halfprivate-halfpublic swimming pool/sports center, 12 euros for a day entry, with a really nice outdoors pool, 10 mins from the airbnb.
It's not far but as it's up quite a high hill indeed you gotta organize a bit with buses or cabs, and also to get food (only a few restaurants around), and then it's easily reachable. U can walk down to Gracia easily, although walking back up is quite a hike!
Joan is super helpful and reactive by whatsapp or emails, his family did a nice welcoming for check in. Don't forget to take a bit of cash for the touristic tax, there's almost no ATMs up the hill and they can be out of service.
A really good deal if you want a somewhat different experience of BCN.