The apartment is great! It is exactly as the pictures show, so the expectations definitely matched. It was also very clean and tidy and we felt very welcome. It is indeed a very cosy apartment. Eli & Agus definitely have eye for detail with small extras such as coffee and tea bags to grab, a fresh bread when we arrived and all the other (small) things you need during your stay. They were very friendly and proactive in the communication before arrival and also during our stay they replied very quickly to a question I sent over email.
The neigbourhood is nice and quiet for an apartment in the city and there are some small supermarkets and bakeries closeby. If you want to walk to the city center, it will take you about 30 minutes, but the closest metro station (monumental) will take you (for example) to plaça universitat, which takes approximately 15 -20 minutes.
We were with five people and the only disadvantage then, is that the people who sleep on the sofa bed, do not really have privacy, since you're laying in the living room. However, if you have good company, it should not really be a problem :)
I would definitely recommend this apartment!