Fantastic bit of worldbuilding and every bit as weird as I was hoping for. There is alot more fantastical elements to this story than Vandermeers previous books. This was a feature to me, while it may not be for others. Be warned though, this ride will be very pulpy and hard to stomach. The beauty is there, it just requires a greater toll.
Addon after completing the series, hopefully this helps someone know what they're getting into:
I would say Borne is great as a standalone and doesn't need any of the other two books. Strange Bird adds a heart breaking and beautiful layer of nuance to the world and makes for a great Duology. Dead Astronauts does for me what Strange Bird did, while requiring a huge cognitive lift to really enjoy.