When this book sticks to what the cover promises -- armored troopers fighting giant ants -- "Armor" is pretty good military sci-fi. But I sense that Steakley was going for something a little deeper in this homage to Heinlein's "Starship Troopers," and in that, I believe he fell short. There are some messages about the cost of war, and the way men and women are forced to turn off their humanity in order to become soldiers, and at times the war against the ants seems like a pretty obvious far future reprise of Vietnam. Soldiers are sent on suicide missions without a clue what their strategy is (and indeed, frequently the war seems to be fought without any strategy beyond "kill Ants"), even to the point of having to sally out from their bunkered FOBs just to rack up a higher body count.
Unfortunately, the middle of the book is completely bogged down by the second main character, who is only mildly interesting and whose scheme to betray the fleet and steal a power source becomes an endless series of interactions between equally unlikeable and boring people.
If you like military SF and don't mind all the characters being morally ambiguous and mostly bastards, this is worth a read, but I didn't find it to be the new SF classic a lot of Steakley's fans seem to think it is.
I'd like to rate this higher, but I found my mind drifting too often as I listened to the audiobook because the story just wasn't holding my attention, so while it probably deserves a 3.5, I'm rounding down rather than up as I usually do.