The apartment is one of the best I've been in on Airbnb, central but pretty quiet (it's Barcelona after all), authentic and stylish, clean, having all the amenities you can wish for.
The balcony is simply to die for, spacious with a great view to Montjuic.
The third bedroom is a bit smaller than on pictures, can be a bit tight for a grown person, but otherwise the apartment is very spacious.
Nicolas and Rosa are great hosts, greet the guests personally even in this challenging times and provide with the local tips and other necessary info for first time Barcelona visitors, so you waste as little time as possible.