The acing was excellent. The plot was very well done, and I recommend the movie highly. However, there was one glaring error that detracted from the historicity of the movie: the scene in which a German installation is attacked and vials of ampicillin are taken in order to treat typhus that had broken out in the Bielski camp could not have happened as protrayed. Ampicillin did not exist in the 1940s, and it wouldn't have been the right drug to treat typhus anyway. In fact, tetracycline, which would have been effective against typhus, was not discovered until several years later.
The acting was outstanding. Viola Davis's acting in her supporting role (Mrs. Miller) was especially noteworthy. Meryl Streep (Sister Aloysius) was first rate, and both Philip Seymour Hoffman (Father Flynn) and Amy Adams (Sister James) were excellent. However, the theme of the movie was a little trite, and the ending was unsatisfying. Also, there was insufficient depth to the two major characters -- Sister Aloysius and Father Flynn.
The movie gave a good depiction of the historical events. However, there should have been some backstory or other indication of what motivated Col. von Stauffenberg. That said, the plot was otherwise well executed. The acting was acceptable but not outstanding. Nevertheless, I would still recommend this movie. Most people know little if anything about the anti-Hitler elements within Germany, and particularly within the German military establishment. In my opinion, this movie, which held my interest even though I was familiar with von Stauffenberg's plot, serves as an effective dramatization of one of the most significant attempts to assassinate Hitler.