The the real reasons to see this movie are two:
The screenplay was written by Dennis Lehane, author of Mystic River, Shutter Island and Gone, Baby, Gone among others. Those three movies, if you have not had the pleasure, are also worth seeing. If you have, a second, even a third viewing only enhances your appreciation for the writing and the performances.
The Drop is based on a Lehane short story Animal Rescue. It is filled with menace and plot twists that will keep you guessing. Lehane is simply one of the best fiction writers of all time.
The second reason is the performance of Tom Hardy, whose previous role as Forrest Bondurant in Lawless really turned me on to this fine actor.
Don't wait for it to turn up on Netflix. See it now.