i got a quote off them for my traffic plus 600 litre system. It was ok on price, and they did understand about wfp systems, which not many insurance brokers do.
In the end i didnt go with them tho, i went with alexander swan, because they do a courtesy van with a thermopure system if yours is stolen or off the road because of an accident.
It was slightly more expensive, but to me that worth paying extra for.