This film is NOT about the Milgram experiment ALONE (the one with shocks and the way we behave when prodded by a person in authority) - and that is what makes this film so interesting! The film is about Stanley Milgram the person. It only starts with his 1961 experiment (which occurred nearly around the same time as the Eichmann trials and Hannah Arendt's writings and hence garnered even more interest). It then continues to show the travails that he passed, his life and how the experiment changed people's perceptions towards him (some interesting reactions here - do watch it and be prepared for the surprises)! For such a popular experiment, there is a surprising lot that many of us (e for certain) may not have known - the film fills in that (large) gap.
There is one big difference between this film and the similar 2015 film "Stanford Prison Experiment" (which I also highly recommend) - This film has a far happier ending and hence makes it even more interesting from a cinematic perspective.
Do watch this film - you will not regret it.