The apartment has a great location. 1 minute walk to metro station Paralel (where you will also find the Montjuic Funicular) and it allows you to go to any interest point quite quickly. It took us about 40 minutes from Passeig de Gracia metro to walk to the apartment.
It was clean and had everything you would need (maybe some extra things in the kitchen for people who plan to cook while visiting).
Overall, it was Ok specially if you are not extremely picky. The furniture is not brand new and maybe it's a style I am not used to, but it didn't bother me. We spend most of the time outside visiting the city anyway.