Well crafted, but way too long. The last hour was draggy and uninteresting as Oppenheimer faced an inquiry to decide whether he could keep his government security clearance. Why this was considered so important in the eyes of the director/writer/editor is a mystery.
Another thing was the close up shots of Oppenheimer looking anxious/upset/pensive or what-have-you. I hate when they overuse them, but that's just me.
Worth a look, maybe put a pot of coffee on first.