We based our decision on which sites we wanted to visit and which club they belonged to, due to work commitments we can only do mainly weekends so need to stay local and the C&CC had a lot more sites in our particluar area.
If you plan to have a few holidays per year it does pay to join both as with the members savings you pretty much get your membership fee back with a weeks stay.
Just to throw in a debate point - I am starting to wonder if there are any real benefits. Does the subscription pay for itself unless you go a lot to the sites? Is the insurance a real benefit or is it just a marketing ploy (ie. could you get the same price if you haggled?). Just a thought..
C & C C membership fees are easily recouped if you join their RAC Arrival scheme - cheaper than normal RAC membership and much better cover. Use the sites for 6 nights or more and you've got your money back. I have always used their ClubCare insurance for my caravans, found it cheaper than elsewhere and they're not so picky about wheel locks. (I haven't found one I can lift and fit yet).
------------- Caz
If you can't see the light at the end of the tunnel, just keep going till you go round the bend.