I am also just at the end of 'Children of Memory' by Adrian Tchaikovsky on audio.
I think my current unpopular SF opinion is that this may be my favorite title so far among his 'Children of Time' series. And it's the ending that sealed it for me. I rather quite enjoy the way this book all came together by the end. I also really love the Corvids as characters.
This also got me to thinking about endings of books. One of my frustrations with a lot of recent books is that I feel that many authors don't really know how to write endings. It's not just that I don't like the ending of the book, it's that I feel there is no actual ending or it's so weak to feel that way.
Too often a 5 star book to me ends up being a 4 or even 3.5 star because the ending just flubs all the goodwill I've given the book.