I have been a member of the CC for nearly 35 years and the C&CC for just 5. However, I rarely use their sites as we spend all our time in the Med, however I do use them for ancillary services. I currently use the C&CC for insuring the van but not CC as they can be very expensive. One thing to note with both Clubs is that discounts will be offered to 'new customers' so chopping and changing can pay dividends. Loyalty means nothing nowadays I am afraid.
The annual fee amounts to about 3 pounds per month, not a lot in the greater scheme of things
Although there has defintely been in increase in people using UK sites this year, Isuspect that fads will change and a few wet summers will get people back to the Costas again, so pitches will become more easily available again. However, there are certain sites where you almost need to be related to someone to get a pitch, not really the ones you want to visit.