Never leave home without it - Four years ago we were suppose to cruise to Alaska. Three weeks prior, DH had a massive heart attack. Insurance refunded everything.
Last year broke my wrist on the Radiance. I don't know what it cost cause RCL ate it as they really were at fault.
January 2012 we took a group of 10. One member did not want to buy insurance. Because of his age, the policy was a bit pricey. At least by Canadian standards. After husband and wife arguing for a couple of weeks, wife called me and said buy it. Being very much on her side I bought it for them. Onboard the Reflection he had heart issues. He was airlifted to San Juan where he spent 2 days in a U.S. hospital then flown home regular air.
Cost onboard $3,000. Airlift n/c thanks to the U.S. Coast Guard, the balance was reimbursed by the insurance company. I did not ask that amount.
I never ever sell a vacation without trying very hard to talk everyone into buying insurance. If they don't, they must sign a waiver saying they refuse.
As far as pre-existing, RBC has a 90 day stable rule and 1 year overnight hospital rule.
OHIP will pay out of province/country the same amount they would locally however that isn't very much by U.S. standards.
I'm going to be on the hunt next year as DH had cancer surgery in April and is undergoing chemo. That means most expensive (which I don't begrudge for him) but also means unless I can find another company, we can't go anywhere before the end of next April.
Which does remind me of a question for my American friends - do your insurance policies had have regulations about hospital stays prior to buying insurance?