I think it's no more/less worth it than human health insurance. We could potentially not use it for years and then boom you get hit with something, usually at the worse time possible. For me personally it is absolutely as essential as my own health insurance. I think VPI is overrated and not great. I've used many different ones and I've stuck with Pets first Healthcare for the last year or two. They are great and the prices are reasonable. I pay $60 for my two:
Pet Insurance from PetFirst Healthcare