There are many things to like about this place. It is exactly as described, even better actually.
The location is hard to beat, as I was able to visit all tourist attractions on foot during the week I stayed there. There is also a quite large supermarket less than 5mn away and several restaurants nearby.
As stated in the listing, the furniture is high quality and the kitchen is furnished with everything you need to cook, with plenty of pots and pans among other things.
José Manuel was very responsive. Every time I had a question whether concerning the apartment or the city, I got an answer within the hour and he made sure my stay was comfortable.
One thing that could be improved is the Internet connection which is quite slow. Still, it is reliable and did not fail once during my stay.
As others noted, there is some noise coming from the street, but the sound isolation from the windows is pretty good. As the street is mainly used by people leaving downtown, this happens at the end of the day and early evening. As a light sleeper, this was an issue I was concerned with, but it ended up not being a big problem.
I will definitely consider staying here again for my next Barcelona trip.