I don't think anyone has knocked the Caravan Cover for claims as it is probably very good, but you are paying a higher premium than with other well respected proper insurance companies. When we claimed from CC many years ago, the following year the premium almost doubled and was close to the price of the repair to the unit.
CAMC was over £100 more expensive than Caravanguard and one needs to remember that with the CAMC cover you do not pay premium tax which was supposed to be a saving. If tax had been added the premium would have cost probably about £150 more!
They also seem to get very expensive if your caravan is over five years old like ours and you want to have new for old cover for the 'van.