I wish you could rate with half or quarter-stars, as I think four is slightly below what this book deserves, but I'm learning to be much, much more picky with my "fives." With that said, I'll list out the reasons that readers with an interest in World War I, the history of firearms, the history of 20th century warfare, "western" armies (the United States, British Empire and Western Europe) ought to dig this one out and give it a go.
1) This book is most decidedly NOT in the "Lost Generation" style, or literary camp, of WWI writing. This is far from the perspective of "All Quiet on the Western Front," "For Whom the Bell Tolls," "dulce et decorum est," and the form of war writing that most readers are probably more familiar with, and this is a good thing. Feel free to be offended by McBride's perspective and lack of contemporary political correctness; he's not forlorn, he's not bitter, shell-shocked (at least not so that it comes through in the writing), nor is he jingoistic or bloodthirsty. He writes in the voice of a professional, career soldier both as a national guardsman and a full-time infantryman and machine gunner, someone who's seen several armies at work. He writes as a professional and as an instructor, for the Indiana National Guard, the Canadian Expeditionary Force, and the inter-war US Army. The wording is straightforward, down to earth, realistic, and if it's seems distant, it's because it is the writing of someone who sees the concept of war, training for war, and the conduct of war, as a matter of fact endeavor. He is content to leave the theorizing to others. We can argue for all time whether his perspective is superior or inferior to the much well known style of WWI writing, but what matters to me is that readers see this perspective in addition to the literary one we know and "love."
2) This book is a look inside the mindset of a mid-western American male at the turn of the 20th century, looking back (circa 1932) because he can possibly "sense" the war clouds forming on the horizon again, and writing as someone who saw the good, the bad, the ugly, the brilliant, the brave and the stupid side of war, and pulls no punches in wanting to prepare his countrymen for it. It's surprisingly lacking in guile and comes across as sincere. That lack of irony (though there is quite a bit of snark) is also refreshing.
3) The practicality and value of expertise, earned experience; if you're not a "gun nut" or obsessed with the minutiae of tactics, you'll find a lot in here you'll want to skip and could probably do so with little loss. However, when it comes to descriptions of infantry tactics, trench life, planning and how the men operated on the attack, on the defense, as a unit and as individuals, it might paint a VERY different picture of the Great War than you're used to, and for that reason, this detail is valuable. McBride doesn't skimp on the horror, or the deadlock of the trench, but his description of raiding and other tactics reveals that the Front (at least portions of it) were far from static, stagnant, endless artillery duels, and also far from cinematic "over the top" slaughters. All of those are gross oversimplifications for what was a complicated, difficult war, and the men who fought and led during it were more often than not, NOT the "upper class twit" or "morose Junker" often depicted (though McBride shows enough of both to imply some justification for the stereotypes, especially as he dissects the good and bad of the British "Tommy" and the aristocratic officer class).
4) Most importantly, and alluding back to my first point, he demystifies the war, something that 100 years on we should be very intent on doing. This is not Tuchman's Guns of August, this is not poetry, nor is it film, nor is song. This is not the pop culture war, this is a memoir of someone who soldiered, and for whom soldiering was his business. No more, no less. The other books I mentioned are valuable for what they are, and my comments are not meant to disparage them, but simply to say that you need more than them to understand this conflict and the men that fought it.
From a personal perspective, it was a bit both relieving, and disappointing, to see many of the same criticisms of US forces looking back on 100-80 years ago, remain valid today. Relieving because it makes me think we're not all that different (speaking as a servicemember) and disappointing, because we truly don't have "lessons learned," merely "lessons identified."