I was once with Direct Line and someone decided mirrors in car parks were optional causing £1500 of damage. Direct Line authorized the repair in minutes. Aviva, or Norwich Union Direct as they used to be known agreed to the repair 18 months later.I was pleasantly surprised when my wife contacted Aviva to tell them that she had a new car to replace her 6 year old one (same make, virtually same model) and they gave her money OFF her current premium, and no sneaky admin charges for doing so either. I think it worked out as about £25 less overall.
However they did then try to put that same premium up by over 15% at her next renewal a few months later, despite no other changes or claims being made, so that kind of took the shine back off my opinion of them quite quickly!
FWIW Direct Line is Churchill, so asking one to beat the other's quote always gets a result.