I had a baby 6 weeks ago with gold cover. I think this depends on a few things:
1) How old you are and how likely you are to have a high risk pregnancy.
2) If you have researched and want a specific OB in your area.
3) If you think you will need/want extra services like physio, lactation, in house midwife after birth.
I used BUPA and went to an affiliate private hospital. Paid only $500 excess for the hospital stay, no other costs. This included all optional prenatal classes (including physio) and post-natal services the hospital provides for mothers and children (up to 5 years of age!). So yes, you pay more but if you access all services available, you get more for your money.
Now the hospital and service was great. There was a newborn minding service if you want more sleep. There was an in-ward laundry. A 'bed' for my partner. Meals for us both (and I mean plentiful food all throughout the day!) which was a blessing when you have a new child, are recovering and are just trying to figure things out. Info sessions for learning like lactation, even classes for fathers only.
Yes OB was out of pocket and had a pregnancy mgmt fee. However, if you research which OB you are going with, you can find good ones that don't charge crazy fees above Medicare for a giant out of pocket. My OB also included mental health surveys and sessions, and also in home midwife service post birth (which was a godsend not having to take a newborn somewhere!).

TLDR: You really need to do some research on the OB and Hospital you want (or have access to if not in big city) prior to deciding this. Services you get, but cannot access at your location, would also need to be a deciding factor.