This was definitely one of Tom Cruise's better movies, and his resemblance to Col. von Stauffenberg was uncanny. I love how the movie was shot in the real places where the events happened (mostly, anyway), and the accuracy was high. I believe history buffs would appreciate that. The plot was crisp and well-written, with the progression beautifully paced. The only 'negative' thing I might have was the distinct lack of German accent in most of the actors. Not that it changes the feel of the movie (Cruise was actually speaking German at the start!) but I would have preferred it more.
Definitely a must-see.