Films depicting prison environments and heists tend to consist of recurrent topics and scenes, and the quality depends on how the viewers perceive them - as clichés or as characteristics. Luckily, Son of a Gun does with the latter, and skillful direction, several twists and versatile ending make this an okay film, where one can not always guess how the things go or what happens next, and all this is carried out without ridiculous shifts.
The cast is international, from a Scot till a Swede, plus locals, of course, and this provides the film with additional value (although the events take place in Australia only). Ewan McGregor as Brendan Lynch is certainly the best of them, outperforming the other main character - JR (performed by a local heartthrob Brenton Thwaites whose apparent intention was showing his torso as much as possible :)); the latter's relationship with Tasha (nicely performed by Alice Vikander) is a perfunctory link at times - although the pre-ending rounds it up again...
But anyway, if you like intense heist films with witty solutions, Son of a Gun is definitely for you.