Susanne, my last 2 cats ended up with 2 completely unrelated conditions, and fortunately Sainsbury's paid out without quibbling, even though Tiger had tests done for both conditions at the same time. I am with Helen that when we are getting up to the limit, I will be considering their quality of life, as they aren't young cats to start with - I wouldnt' recommend Sainsbury's to people with young cats though, as you have a higher risk of having to pay.
If I remember rightly, Animal Friends are underwritten by E & L, and they dont have a good reputation.