I stayed there for 5 nights. This place is more than the expected for a hostel.
This is probably one of the best hostels I've been. Clean rooms, bathroom with shower in the big rooms, friendly staff (they act as touristic office, even selling tickets for attractions in Amsterdam) and the best breakfast I've ever had in a hostel. The installations are completely clean.
Smoking is not allowed and windows can´t be completely opened (I can imagine why, but I think that the stuff with the windows is a bit excesive).