I got an extremely small room with the window towards the inner entrance hall (staircase). This meant cigarette smoke reeking in, and voices of all visitors coming and leaving.
The AC was just over the bed, and I slept very badly because it was always either freezing or too warm. Opening the window was not an option, see above.
There was only one (1) shared toilet/shower on the floor, so if somebody was showering - then nobody could use the toilet for that while.
There is no elevator.
The room safe was not functioning.
The reception is open all day, the staff is very nice and friendly. They did their best to help, and make me feel welcome.
There is a very good and reasonably priced bar with food and drinks just outside of the front door.
Location is awesome, just beside the subway, and the Rambla pulsing with shops, sightseeing, nightlife!
The place was reasonably clean and reasonably quiet. The building is beautiful. The roof was equipped with a TV, a wardrobe, and a handwash despite its tiny size.
All in all, the hostel gives good value for the low cost, but nothing more than a place to briefly stay the night in between your Barcelona adventures. If you are used to any kind of luxury, you should not choose it.