I chose not to purchase it. O.k., I guess technically I'm young enough that I could change my mind and purchase it if I wanted to, but I doubt that I will.
It's been a while since I looked into it, but a couple of things turned me off. I didn't see any options that offered level premiums. So the premiums could keep going up and up without limit as you get older. Also, the policies had 90 day waiting periods before the benefits kicked in. So you would be on the hook for three months of nursing home expenses before the policy paid anything. Many people who go into nursing homes don't last that long.
My plan is to reduce my withdrawal rate below what historical simulations say I could withdraw, and let the buffer compound over time. By the time I reach my normal life expectancy, I should have multiple hundreds of thousands left over as insurance against longevity and/or long term care. Or if I don't need it, it passes to my heirs.
Not sure I would really call this self-insurance, as the plan definitely has risks. The biggest risk is if something happens years or decades before I or my wife reach normal life expectancy and we have to shell out for nursing home care before the excess money has had time to compound. That could leave the healthy spouse drained of assets with decades of life left to go. If that happens, the healthy spouse could sell the house and live a meager SS-funded existence. Not ideal, but doable.