We had a really nice stay and both my wife and I agreed it's the nicest AirBnb we have stayed at. We got a nice "homey" feeling and the fact that our 2 year old got lots of toys to play with (even her own little kitchen which she loooved) made everything easier for us. Rosa was very nice and welcoming and took her time giving us tips on what to see during our stay.
Super clean apartment and decent size too, just what we needed. Location is great, you're within walking distance if you don't mind walking 20-30 minutes to get to main attractions. We did not take one ride with any public transport for the duration of our stay.
The apartment has pretty much anything you need. Nice coffee and teas, good quality towels, great kitchen and a large new smart-TV. There's a small but nice balcony to enjoy too, although the weather didn't permit us to use it all that much.
The beach is super close and we spent a lot of time there even though it was pretty cold.
Fun fact (not checked) but our taxi driver from airport to apartment told us the building where the apartment is located in hosted, among others, "Magic" Johnson during the Olympics.
It's the easiest thing for us to recommend Rosa's apartment to anyone who wants a nice stay in Barcelona.