When is a fixed land line a waste of time if you need to have Priority Assist for it? When you have anything that doesn't use the Wall Panel with the Uni-V socket. This means HFC, FTTN, FTTK, FTTB, WiFi, and Satellite are not going to get it even if you use a provider who is a PA RSP.
This is the answer from NBN's pages about it:
"People who rely on a landline phone service should opt for a phone service provider that connects phone services through the nbn™ "Uni-V" port. Standard phones that don't need to be plugged in to a power point can be connected to the UNI-V port and supported by the nbn™ battery backup unit."
That's all well and good if you get FTTP but if you get anything else it won't matter who you use as none of the other technologies get the wall panel. NBN Useless yet again!