Stayed here with a friend at the end of January in a 4 bed mixed dorm. Reception staff were friendly enough. The room was actually slightly bigger than I thought it would be, judging by the pictures and the shower/toilet/sink were all very clean. Not having wifi in the room was a litlle annoying but didn't really matter. Tried the breakfast once, wasn't great to be honest.
Didn't really spend much time in the hostel but it was a nice place to be based. It was handy how the free walking tour started from the reception.
Would definitely stay here again if returning to Amsterdam however I would probably get a private room as sharing with two random people was a very slight inconveniencenat times.