CROW by Phillip Richards is one of those "grim scifi combat" books that's comparable to Rick Shelley's "Lucky 13th" Series, where the tech isn't that far from our own, or perhaps the "Starfist" series by Sherman and Cragg. In fact, warfare had changed very little in the CROWverse. Infantry still use guns (albeit, miniature railguns), and air support is now exclusively via UAV, but otherwise, little has changed. It's still grenades, missile launchers, and cold steel (i.e. bayonets).
The setup is generic enough. The Union (whose military seem to be almost exclusively British) is invading "New Earth" to take it back from the Chinese, who had invaded it a few years back and kicked out the Union forces. Now the Union is going back, and the recruits, such as the narrator/hero Andrew Moralee, fresh out of basic training, and dumped onto dropship infantry. During the voyage he's hazed and bullied, and once on the ground, he fought and cowered and cried and killed and watched friends die, and was changed forever.
While the story was supposed to be scifi, by replacing a few terms it could have been describing British action in Afghanistan or British invasion of the Falklands. The enemies are generic enough, and the tech wasn't given much thought (no power packs in these railguns, eh?) I mean, the tech described in here is less advanced than Call of Duty Advanced Warfare with exoskeletons and jumppacks and smart rifles and such. Seems section leaders have smart grenade launchers on their rifles, but otherwise there's very little tech.
Frankly, there's really very little in this book that stands out other than it's British. All the military terms are British, and all the characters seems to be British. It's as if the author is trying to tell his own story in an allegorical way, without much of a conflict, climax, and resolution.
If you want grim and scifi, with good action, maybe you should read David Drake's Hammer's Slammers series instead, or perhaps Starfist series. I find it difficult to recommend this book, though I guess the next book may be better now that the introduction / world building stuff is done.