There were so many brilliant decisions made in this movie, but starting with a black screen over a minute's worth of sounds from 9/11may have been the best. No need to replay the images we've seen a thousand times.
Letting Jessica Chastain carry the film also produced the best end result even though many filmmakers would be tempted to widen the narrative to include the politics surrounding the events. Every moment she's on screen, she's working on one objective and the resulting buildup of frustration and tension is amazing given we already know the ending of the story. Cutting away from Chastain for much of the final third of the film is equally brilliant, as it gives center stage to one of the best action scenes ever filmed and one that we've been excited to see for the last year. Absolutely worth seeing it on the big screen while you can.