I thought Nation was awesome for the first half or so. But then somewhere along the way it stopped being about Mau and started being about Daphne's father.
Much of
Nation I found to be very enjoyable - but the story suffered in not being sure whether to be serious, or a comedy. Pratchett seemed to be confused about what message he was trying to convey.
Mau's scenes were deep and reflective and the tribes people were very well done. Daphne was simply over-the-top caricature. There were footnotes that broke any narrative mood. The last few chapters just came across as a jabbering jumble, and the story simply withered away.
The main theme of the book appeared to be reason and faith - as if Pratchett was trying to make a big statement about his own beliefs. He openly states that Man has made God, because Man must believe in something - that belief in Reason can replace belief in God. And yet Mau still experiences the spiritual and supernatural. IMO to tell the one but show the other is a contradiction.
The structure didn't make sense either - the opening scene was all about a global plague. Then, about two-thirds of the way through, Pratchett seemed to suddenly realise that he'd forgotten to write in Cox as an antagonist and rushed in some backstory ready for Cox's appearance in the next chapter. The plague subplot never amounted to anything. I don't understand why he didn't just write in the mutiny as the opening scene, and dispense with the plague idea completely.
I read
Nation because Terry Pratchett said that of all the books he'd written, this was his favourite. I did find it interesting - but, ultimately, confused about what it wanted to be, what it wanted to say, and how it wanted to say it. Somewhere in here is a really great story, but its smothered in farce.
I'm minded to think that he did a better and clearer job addressing faith with
Small Gods.