I stayed in a single room on the upper floor. This place is good in many ways: low price for being in Longyearbyen, the included breakfast is simple but nourishing and more than OK. Free coffee with condiments 24/7. Canteen kitchen worked okay. Good TV rooms and lots of general surfaces to socialise with the others who visit this kind of odd Arctic location. Friendly personnel and reception too. You can buy beer and wine for a "moderate bar price" from the reception - think 45 nok for a standard big can of lager.
The location of the hostel is not very good if you want to frequent downtown. It's essentially a 20 minute walk in good weather. This includes a 800-meter stretch of road without any houses, it is lit with street lighting but during the dark season this can anyway be a slightly eerie experience, playing with the thought that polar bears might be nearby. That aside, from the hostel it is only a little more than five minutes walk to the worlds northernmost, and surprisingly very great nightclub, Huset (open fri/sat night).
Also, the hostel's "off" location means you have less light pollution for seeing northern lights. This is good.
The not so good: Slightly musty smell in entire hostel (not only me thought so but a couple other travelers too, something with the construction material maybe?) - Water heater set dangerously high; burnt myself by accident a couple of times when washing hands.