Most of the reviews here are spot on. I watched it because the three main actors (Glazer, Theroux, and Bronson) have been great in everything I've seen them. And they were also great in this, given then the script.
I sort of knew going in what the plot was and expected the outcome. The heavy handedness of the moral was off-putting. (Edit: especially the peripheral actors. You know what's coming about 5 minutes in.)
As others have said, it would have been better as a short film. I wouldn't give it 1 or 2 stars like others because the acting was great, and there is a great story here that seems so have not been properly given real thought.