I can , from personal experience of claiming, quite clearly state that the Caravan Club insurance is by far the best available, albeit at a slightly higher premium, but without ridiculous security clauses like the van being wheel locked when stopping for more than an hour, or the use of both hitchlock and wheel lock.
I have had 3 claims over a period of time and on each occasion the claim has been dealt with and the van repaired within a week.
The last claim I had was for a full new side to my van, and the claim was agreed on the phone as I spoke to the Insurers.
I know the company Dustydog refers to and it is true, they have an appalling record of dealing with claims, but we are not allowed to name them as they have stated that ANY mention of them will result in legal action being taken.