So glad this thread is still active. Just watched two gangster movies back to back: "Gangster Squad" and "Lawless".
The latter is certainly a deaper movie with believable characters and very good acting by Tom Hardy and Guy Pearce. Great 1920's vintage cars on display too!
Gangster squad is almost like a comic book, with its saturated primary-colour visuals very similar to Dick Tracy but sadly with one dimensional characters and over the top violence.