Agree with most of above. Cool Camping was a great idea but has proved to be so popular that a lot of the camp sites have been ruined by their new found popularity. The sites offering the most basic facilities seem less affected.
If you join the C&CC you can get discounts in many camping shops, decent discounts on ferries and EuroTunnel too. Plus reduced rate pitches on their sites. It’s certainly worth joining if you plan on going over to Europe.
Also remember that not all sites are in the camping guide books. This place is usually good for suggesting campsites if you’re heading somewhere new.