Marion Cotillard, yeah, she's one of those people that you know you've seen her before but you can't exactly place her and it tortures you for the duration of the film.
She also looks so much like she was actually from The Greatest Generation that she's probably one of those actors that can morph with every role she's in. And, looking at her on IMDB, I've actually seen her more than I thought I had.
At any rate, she blends well with the era...but, unfortunately, Pitt looks less from the times than he did in his other WWII movies, which is odd given how he can blend as well. I guess the producers wanted to feature him more for the draw of Brad Pitt.
In either case, it is a suspenseful and emotional film and one that will sit among the better spy movies ever made. It's low key, the action and the violence is down played to the point where it's far removed from Bond and comes across as a very straight spy thriller.
In other words it's the type of movie we unfortunately don't see enough of these days, subtle and straight. It's a movie that is based around the characters, the script, and the acting more than special effects and because of that it's easy to get involved emotionally with the plot and the people, even if it does move a bit faster than I would have liked.
Overall, it's a breath of fresh air in the era of the MCU and over-the-top effects and it pays off in the end from pure emotion. You can't get much better.