I don't know enough about the individual battles to comment on their accuracy, but the narration was clear and straightforward. The overview of the battles is clearly meant for those who know little about them; this documentary might be too simple for those who have studied WWII battles. It was interesting to see so much real footage of the battles and realize they still don't come close to imparting the terror of actually being present for any of the battles. Most importantly, I learned some new things from this documentary so I'm glad I watched it.
One note -- the CC/subtitles had a lot of blatant errors, especially for important names related to the battles (e.g. "Honate" instead of "Hornet") which was frustrating.