I liked it, I can't say I didn't see the ending coming from the last book but that's not necessarily a bad thing. It ended about the only way it could have what with all of the proto-molecule and cosmic horror stuff that gets built on in the later books.

Also you should definitely pick it up again, there are a few of the most impactful moments in all the sci-fi I have ever read in terms of character development and story arcs along the way. The fifth book seems like a bit of a departure from the overall narrative but it is actually necessary to drive the events of the remaining half of the story and is interesting in its own right, much more character focused and the crew spends most of it separated by circumstance.