If you were to take out all of the songs, hymns, prayers, and poems that are quoted in the text, the book would slim down by a good 20%. Now, such things can give context and texture to a story, but enough already. A 7 or 8 verse song/poem (and there's more than one) is a sign that a heavier-handed editor is needed. Also, if you have been reading the entire series thus far, a good bit of the descriptions of bow making & so on have been covered at length in previous volumes.
The story seems unevenly paced; there will be a LONG description of, say, the craft of scouting (similar to a number of passages we've already read in previous books) and then a dramatic plot event will be all but skipped over. For example, a character is killed while in the care of one group of our story's protagonists. Yet, when the protagonists rejoin the family of the dead character (whose death causes a good bit of anguish on the part of a main character), presumably there is a dramatic interchange between these two - the sad telling of the news, the family's reaction, etc. But as far as the text is concerned, the two groups merely reassemble, serenely spend a little more time together, and then part ways again.
While Stirling has clearly thought out what a post-technological society might become, I have a quibble with a few of the conclusions he has reached - namely, that all morally good, intelligent people will come to the same conclusions. All the splinter groups - the people who take on the trappings of Ancient Greece, the Wiccans, etc - they fall deeply into these identities, even those who were adults at the time of the Change. I just don't see how this would be natural - for a modern, contemporary person to become, in 22 years, a peplos-wearing person who swears by Minerva and Jupiter, or a plaid-wearing person who thinks of the Lady and devoutly follows Wiccan practices. Maybe the attire makes sense, and I can see how the people born after the Change, or those who were kids, would buy completely into the splinter society's identity, but for those who were adults and became adults in our contemporary society? I don't see that kind of thing being so fluid. Also, I find it odd that people everywhere in this new, splintered remnant of our current world - where there is no real long distance communication, and no more common society (what with all the tribal identity stuff) use the same terms to refer to certain things - 'the Change', 'the Eaters'. Common sense says that there would be different terms for these. Even today, with mass worldwide communication, the events of Sept. 11 are referred to in a number of different ways - '9-11', 'the WTC bombing', 'September 11th', '911', etc. But in Changeverse, everybody everywhere uses the same terms.
The author does have a boundless imagination. This IS an interesting series, but I give Scourge of God 3 stars as it feels like a place holder to me. I don't mind the fantasy elements (the demonic possession, the hint of extraterrestrial interest in Earth as a cause of the Change, etc). I will almost certainly read the rest of the books, but am keenly hoping that this series isn't stretched out much more than it has been already.