And while others have been less than kind about Ruben Fleischer's 'inspired by real events' story of ambitious mobsters, corrupt cops and the few good men who took a stand, I left the cinema wondering what they were expecting.
Because what you get is a slick, stylish, (mostly) fast-paced film that owes a huge, fond debt more to the gangster films of old than any real events.
Yes, some of the dialogue is hokey ("You're talking to God, so you might as well swear to me" HONK! "This isn't a crime-wave, it's an enemy occupation" HONK!). Yes, you've no idea what Sean Penn says as he prepares to show some poor unfortunate what it's like to be caught between two cars ("muttermumblemuttermumbleCHICAGO"). Sure, the wonderful Emma Stone is channelling every last femme fatale from Hollywood's golden era - but that's half the fun.
This is not a film that is taking itself too seriously.
OK, the Josh Brolin narration at the start and finish gives it a faux air of gravitas that is as unwelcome as it is unwarranted, but in between things go bang, baddies go splat, Stone and Ryan Gosling come together almost politely - it's all good stuff.
If I had one reservation going into this, it was Brolin. Never a fan of his more wooden style of acting, I really didn't think he had what it took to be the focal point of the ensemble cast. Not while Sean Penn was around.
But I couldn't have been more wrong. In a remarkably restrained performance, Brolin comes across well as the chisel-jawed good cop who's badge is more than a piece of metal. Granted, the role isn't exactly taxing, but he delivers and delivers well.
Which is more than can be said of Penn.
All I can assume is he spent a lot of his time 'researching' with Jack Nicholson and a stack of comic books, because his portrayal of Mickey Cohen - the man who decides to take over LA by stealth, then force, then from an entire hotel - is straight out of the caricature school of acting.
The fact it doesn't actually derail anything is testament to the other actors.
Even The Actor Formerly Known As Nick Nolte looks like he vaguely knows what he's doing. Granted these days he has the screen presence of a bag of onions, and you do feel that at any minute he could just stare at the camera wondering where he is, but he manages to string enough believable sentences together to drive the plot along.
There is a feeling of style over substance here, certainly, but what style! Shoot-outs galore, a full-throttled car chase in cars not built for such things, swanky restaurants... Gangster Squad was never going for the gritty, even if the blood does flow like champagne.
Yes bits are hokey, yes bits are dumb - but there are laughs here. The attempted jail break, the shoot-out scene in the hotel lobby (Best Use Of Baubles In A Movie at next year's Oscars, you mark my words), the car chase with added grenades - they all serve to put a grin on your face.
As with most films these days, it gets a bit baggy in places and could have benefited from a bit of tighter editing, but overall it looks great and some of the fight scenes are brilliantly executed.
Possibly my new favourite Christmas movie.