I don't know. People keep complaining about Cibola Burn (book 4), but I liked it. I genuinely consider it one of the better ones.
That's perhaps because it's the first, and to date the most detailed, exploration of the aliens and their technology, which to me is the most interesting part (after Earth-Mars politics).
But then, I'm the weird guy who thinks character development is overrated, and reads sci-fi for the ideas.
The whole series is like a tease. I like book 4 a lot too because I started reading this series to read about alien monstrosities, etc. Then the next three books turn back into a political theatre and it only gets good again in book 8 when they start looking at different alien systems. The series should have been a lot less books, but it makes sense the writers themselves have said they have the whole story in mind, up to the last sentence, and they’re just adding in pacing. I think it’d be better to have a trilogy with the first two books, the second two and then the last trilogy (no need for books 4&5 since, as I said, I’m wanting to read about an ancient alien civilization.)
That's perhaps because it's the first, and to date the most detailed, exploration of the aliens and their technology, which to me is the most interesting part (after Earth-Mars politics).
But then, I'm the weird guy who thinks character development is overrated, and reads sci-fi for the ideas.