The show's fine if you never read a single book or knew anything about the topic. It gives a good overview and has nice maps and illustrations. The dramatizations are lazily made, and they get reused a lot. From episode to another, even while talking about different things. Same goes for the interviews. They use soundbites intended to be used in reference to a specific event in one episode, as a descriptor of "the frontier" as a whole in another. Just feels cheap.
I agree with the review about the weird white guilt tripping. I'm not denying any of the atrocities committed, but the show has this weird double standard that ends up feeling pretty racist in itself. Almost like white people are the "adults" of the world that more should be expected of, where as the native americans are these naive savages lower standards should be applied to.
The show correctly points out that "native american" is this anachronistic term invented by the Europeans to group all the native americans into one group. The native americans did not see themselves as part of this a large collective, but rather as members of their tribes. Tribes that were often at war with each other, fighting over land and resources. But when they do it, that's just "the way things were". When whites introduced themselves into this battle for land and resources, it's "theft" and an "invasion" for taking land that "rightfully" belongs to the native population. Rightfully, because they won it in a war some years earlier.
Some of the historians they interview seem to be fully aware of this, and paint the Westward expansion of the US as an extension of larger world history where conquest through might was the norm regardless of nation or race. Others seem to be totally oblivious. This results in a weird tonal mess.