In reply to davkeo:
I've only stayed once at one of the campsites there (I think the Laacher See but I could be wrong)
It was fine and well situated on a lakeside with good food & beer
BUT, at the time they had the most unbelievably bureaucratic arriving and registering that we've ever seen
I seem to remember that each tent had to have someone go there at 15:00, queue up to check-in
this put a large dent in the time for climbing
I wouldn't go again if they still have this system
Maybe HansStuttgart has more recent information