This film commits the cardinal sin of not knowing what it is, or what it's about, and consequently ending up being about nothing. Certainly nothing anyone cares about.
It certainly adds nothing to the infamous 1974 incident during Frank Sinatra's Sydney visit. It pretty well retells what happened then, while adding some not very interesting fictional characters, involved in a completely conventional and by-the-numbers "romantic comedy" plot.
Dennis Hopper, one of the most charismatic film actors alive, plays Frank Sinatra, one of the most charismatic singer/actors ever, and make both of them dull. There are a few sparks of fire, but his wooden impersonation of Sinatra singing is like watching a rather stiff marionette. One is left wondering why Hopper and Melanie Griffiths bothered. Are they that desperate for money? Or did they really, really, really want a free trip down under?
Joel Edgerton and Rose Byrne are their usual competent selves in the sub (or is it main?) plot, but it's SO conventional and predictable, one also wonders why they bothered.
As for David Field as Bob Hawke ... while it's certainly arguable that Hawke is/was a buffoon in many ways, he has never been the boorish clown depicted here.
The script is the villain. It's an idea --- and not a very strong one -- which has been developed into .... what? Certainly nothing Australian audiences want to see, as evidenced by the box office returns.
The only person to come out of this completely triumphantly is Tom Burlinson, who supplies the Sinatra vocals. If you didn't know it was him, you would swear you were listening to the Chairman of the Board himself, and on a day when he was in fine voice.
5 out of 10, and I think I'm being generous.