I got a single room at this hostel. It was large, the bathroom was clean, and the bed was comfortable. Breakfast was good, including croissants, sandwich meat, fruit, yogurt, and coffee.
It is about a 10 minute walk from the Metro, but it is really hard to push a wheeled suitcase, as the sidewalks have small square patterns embedded in them. This is a problem in many Barcelona neighbourhoods, and is not a reflection of the hostel (just a warning about the walk there).
The hostel uses recycled water in the toilets and showers, but the tap water is potable.