Not sure why I'm asked about claims, as I've not made any! Our Great Dane puppy broke a back leg aged 5-6 weeks while at the breeder, (fully healed now), and she may have claimed.
I continued with the KC insurance, A. Because they were already aware of his problem; B. They were able to insure him, some companies wouldn't insure him because of the break, (and AT LEAST one just wouldn't insure GD's!); C. The KC said if Monty had no problems with his leg for 2 years, after that time any injury to that leg would be treated as a new injury and would be covered. All in all, I have hesitation in recommending Kennel Club insurance.