It's a quality series and this program is up to par. I'd rank it alongside the first two seasons of "Battleground," and in many ways an improvement over "The World At War." The "Battlefield" series is as effective as this but in a different way. "Battlefield" is more clearly organized and describes events systematically from the top down, beginning with "The Leaders." After the political background is sketched in, the programs concentrate on the actual battles, describing the size and condition of troops on all sides and the particular weapons available. Good use is made of maps.
This series, at least so far, has been less explicit about troops movements and the like and more conjectural about the motives of the participants. Eg., after the war with the USSR, Finland was exhausted and Stalin could have occupied the entire country and set up a communist government. He didn't. And "The Complete History" speculates about what kept him from doing so. Not that this series neglects the subjects so well covered in "Battlefield," just that the material is integrated into a more general narrative.
As usual, there are no talking heads, only combat footage, and the narration is balanced and easily understood. A great deal of the footage is surprisingly unfamiliar. We don't hear about units being moved around on a map like pieces on a chess board. The presentation is "balanced" in that it not only describes the actions of the enemy but gives the reasons for them. And it doesn't excuse the shenanigans of the Allies. "If Germany violated Norwegian neutrality, so did Britain and France." The musical score is used profligately, sometimes threatening to overwhelm the narration.
The description of Neville Chamberlain's humiliation is touching. The worst move he ever made was waving that damned piece of paper while the cameras rolled and pronouncing, "Peace in our time." When he gave the Sudetenland to Germany, he represented the belief of almost all British and French that war could be avoided. Now, his reputation in tatters, he was sent out of Parliament to the chant of "Go! Go! Go!"