It really comes down to personal preference. I for one wouldn't be without it, to us it is as essential as car and house insurance.. But there are plenty of others who will argue that it isn't necessary.

At the moment (except for having both babies privately), we haven't used the equivalent to what we have paid, but both DH and I have not paid to go to the dentist twice a year for the last 4 years, I paid $20 for 2 pairs of glasses a few months ago. I have wisdom teeth that need to be removed, but I am able to wait till it suits me, and my family to help with the kids if I require it. (they aren't causing any pain, but are there). So for us, I would say it comes down to freedom of doing things when it suits us vs having to wait, and then maybe being called up when it doesn't suit.