My family has extras cover, for Dental and Optical, that's all we ever use. My wife and I have both used up enough dental to make it worthwhile. But my son is getting braces soon which will basically Max out his lifetime orthodontics cover. So at that point we need to change insurers.
On a tangent I don't get lifetime covers. It seems like they are so focussed on not letting an individual recipient cost them more than an approved amount that they instead cause recipients to jump ship once it's used up without contributing any more into the fund. That seems like a perverse incentive to me, or am I ignorant of some gotcha there?