This book is so silly it deserves laughing at. So if you're a fan that reads Stirling uncritically, then stop reading now. Don't get me wrong, I read some of his stuff years ago that was excellent, and I generally quite like military S. F. and out of time stuff. But in that series people and practical problems and dealt with them in a practical way. This is nothing like that.
The scenario is this. Something has happened that stops stuff exploding, cannibalism is rife, and rugby has gained a goalkeeper who wears a helmet, so we're all cast back to mediaeval times. Well that's it in a nutshell -- not necessarily a bad idea, although the physics are suspect to say the least, so we might classify this as fantasy rather than science fiction.
The problem is not with the scenario, but what he makes of it. Parts of Oregon seem to be run by Wiccans and the sort of people who go to Renaissance fairs. Middle America will love this. They even say things like "Merry met" and " Ho, Samkin" and stuff. The archery instructor, who used to be with the SAS, says "let the grey geese fly"!!. Just as well he is tough, because otherwise someone would hold his head under water until he promised not to say that any more.
Not only that, but England is being run by King Charles the third. What ever gave him the idea that the Pom's would revert to tugging the old forelock to the gentry, particularly those who end a sentence with "what". Charles can't even pick his clothes up of the floor for god's sake, and I tell you what, homoeopathy ain't going to do much for a sword cut across the guts. I suspect it would be more a case of "throw another prince on the barbie." What is it about Americans and the British aristocracy - every second book a right has kings and emperors, lords and ladies - they should be glad they got rid of them. And Stirling shouldn't try northern dialect, it doesn't work chook, sorry.
This applies to the Aussies too. While I am genuinely appreciative of having people from my part of the world included in the book, I can't imagine any Australian saying "it's a big drongo of the ship". He'd be next on the barbie after Big Ears. Thank God he doesn't get started on us Kiwis.
I'm afraid the rest of the book i.e. fighting , which what we all sign up for, is merely okay, and largely derivative. Been done better. Stirling seems to think for instance that someone with a home-made bow can put 90% of their arrows inside a 2 inch strip at 250 yards. I suspect not - to say the least. And if I'm going to be picky about military matters, the SAS don't use the SA80. If you're writing military science fiction it pays to get that sort of thing right, because many of the people who read it are going to be knowledgeable, and anal retentive about that sort of thing. All in all, he's lost the plot. This book is worth reading perhaps if nothing better is available, but there is far better stuff out there.