The room is clean, not very big but perfect for one person or couple, quiet and has its own window (not systematic in Barcelona). It gives a comfortable privacy.
The flat is in a modern building with a lift. It is pretty big with funcional kitchen and really pleasant living room and balcony. Might be a bit noisy because of the street but nothing bothering really.
The location is great IMO, 10 minutes walk from Sants station, 20 minutes from city center.
And the hosts are really kind and helpful. Also the price is very correct.
The only thing to know is that there is a cat a bit crazy :-) It was a good experience and I would definitely recommend this place.