I'm curous that Optus posted (and withdrew) some new plans late last night.
Under the "Just Broadband" tab there were now new clickable squares for what tier you wanted. Basic, 1 , 2 (50/20) or 3. It does seem Optus are (or have) considered a straight forward broadband offering. There was no indication if these plans would be properly provisioned for peak hour bandwidth or just the same as any other Optus plans. I'm guessing the later as any network with UNLIMITED plans basically has no control over how many users will suck down how much data in a given month.
I'm unclear whether Optus (or any Telco) have the technical ability to guarantee bandwidth on an individual plan basis? Obviously they can speed limit individual plans? But it seems speed guaranteeing is not something the network is setup to do? The bandwidth Optus purchases from NBNCo (in monthly slabs) is shared between all Optus customers.