It CAN be so confusing. I find the best way is to ask people in a similar situation to yourself which insurer they use and are they happy? After you have asked around long enough you start to get a feel for what people are experiencing.

We have had PHI (private health insurance) for about 12 years now. We have only been with NIB and are very happy with them. We mainly use it for the dental cover and as we are a family of 5 we almost recoup our premiums by what we save at the dentist and optometrist each year alone! Our policy refunds us 80% of each visit. HOWEVER we recieve a discount on the premiums because DH's employer (a bank) gets a staff discount. We also have hospital cover and it came in handy recently when DH needed a sudden hernia operation... if we were public patients he would still be on a waiting list... he had the op within a week of it being diagnosed... $200 out of pocket expense.

Remember that if you have full PHI you wont need to pay as much Medicare Levy which might or might not save you $ at tax time.

Goodluck with your research.

ETA: Marcellus is right; you do usually need to pay more than basic Extras to get cover for braces. I'm not sure we are covered... but then again my kids probably wont be needing them according to what our dentist has already said.... phew!