Short story:

I have one of my cats insured with them as I was initially attracted by the relatively low price of their Premier Lifetime Cover. After making claims this year my monthly premium is 153% higher for next year!

Long story:

Unfortunately my cat developed ongoing stomach problems, diarrhea, weight loss... to start with I was mostly making small claims as the vets tried short courses of antibiotics, wormers, etc. All covered no problem. Small increases on each renewal, which was fair. This year the cat's insurance was £30 per month, which is much more than I pay through another insurer for my other cats, but seemed well worth it considering his ongoing health issues.

However during the last year his condition got much worse and he had to be referred for more extensive tests, including ultrasound and hospitalisation fees he probably incurred treatment costs of around £1500+ this past year. Again More Than paid up (minus excess) without trouble.
However like many other customers I was in for an eye-watering shock when I got the renewal paperwork for next year - PREMIUMS WENT UP FROM £30 TO £76 PER MONTH! That's a jump from an annual cost of £360 to £912 in one year! Clearly they plan on scraping back every penny they have paid over the next year or two.

Fortunately the cat is improving rapidly, but I am now facing having to cancel his policy and the daunting prospect of covering uncertain future vet bills from my own savings, because 'pre-existing condition' exclusions mean no other insurer will cover him. Clearly More Than think this means they have me cornered and can charge what they like.

Conclusion:

I always thought insurance was a gamble where most pets stay well and the insurer makes money off the customer, vs a few pets who get ill and then the insurer pays out more than the customer. It seems with More Than they intend to make sure the customers ALWAYS pays more in the long run no matter what, so where is the incentive to buy insurance if you are always going to lose money in the end even if your pet gets ill?

Other insurers such at PetPlan state that they will never increase your premium because you made a claim. How I wish I had put more weight on that feature when choosing my insurer!