I have never stayed there, however as I used to live in the area, I have seen it and while studying applied for a job there as security guard.
I did not take the job as the expectation was set rightly by the manager: Keeping an eye on British, Dutch and German teens drinking all night long.
I do know they have separated this "youth" area from the rest of the camp site, so families should be alright I guess. There is quite a lot to do in terms of recreation for kids as it is way more than just a camp site.
If you haven't already, do have a look at
www.duinrell.nl
I wouldn't agree it's near Amsterdam, as it is actually in The Hague, but then again, you're probably talking about only 40 kms from Amsterdam anyway. Enjoy your stay in Holland.