I've been with Petsbest insurance for 8-9 years or so and have been satisfied with their service. Other than one claim where my dog ate something she wasn't suppose to, I would recommend their service. My advice would be for potential customers is to read and understand the policy. You don't want to get caught by surprise - in any insurance policy.
One incident recently (day after Christmas) the policy saved my bacon. My dog suffered hemorrhagic gastroenteritis and her normal vet office was closed so had to take her to a 24/7 emergency hospital. After a two day stay, she was out of the danger zone but the bill was astronomical. But Petsbest paid out in two weeks.