My wife, daughter, and I just spent three nights at the StayOkay. It was...OK. We chose the StayOkay because it promised bike rentals and is located very close to a magnificent area for biking in the dunes. We weren't expecting anything fancy...and that's almost what we got. Some positives:
1) very friendly staff. They addressed (or tried to address) most of the problems we encountered. They sell bus tickets and maps. They put us in our own "family room" and plied us with complimentary drinks and lunch sacks when things didn't go as planned.
2) serviceable Dutch breakfast included (breads, cheeses, etc) No fruit or hot food but tasty and filling.
3) Clean.

Some negatives:
1) even though we made the reservations in advance, our bikes were NOT ready. There was something wrong with 2 of the 3 they had selected for us. In fact, our daughter's was not rideable. This was a BIG disapointment and we had to waste a couple hours sorting that out and going downtown to rent from a real shop.
2) Location. The hostel is about 20 minutes out of town in a surburan part of town and easy to reach by bus BUT given that we were there to use the bikes, that 20 minutes seemed like a drag.
3) Value: for three of us it cost about 100 Euros a night. For about the same cost we could have stayed in a hotel and not needed to bring our own soap and towels OR slept in bunk beds.
4) Noise: our room was right near the entrance door for the sleeping hall. So...we got to hear that door open and close a lot...which was more annoying than the sporadic conversations in the hall (a problem in ALL hotels, yes?)