Christopher McQuarrie 2015 interview on making TWOTG
http://www.denofgeek.com/movies/christopher-mcquarrie/35730/christopher-mcquarrie-interview-the-way-of-the-gun
Why he made the film, how he cast the film, the production, and what he learned overall.
Personally I think he's too critical. There are hundreds and hundreds of films made every year, just in the USA, that we barely hear about. Some are never heard of again. But this little film has a cult following which includes me. It's a great film to watch with friends.
I think it was before its time.
It's not what a movie is about, it's how it is about it.
RIP Roger Ebert