It’s bigger than anything we’ve used before - and the advantage is interoperability with the rest of the RAAF fleet and with the Qantas fleet as well (I haven’t checked but in the past Qantas has been involved in maintaining the RAAF’s large jet fleet).
I hope the Prime Minister's aircraft will feature the lyrics of Waltzing Matilda on the side,it being the second greatest "national anthem" of all (after The Star Spangled Banner,of course).