Mechanically well done, dialogue exceptional, plot believable and tense (in just the right places)...but for me, it was the character development that really shot this one through the roof. When you love and hate (Ramirez) the characters, you know the author has done what it takes to make them feel real.
As former military, I also appreciated the accuracy of the terminology and the genuine feel of military personnel. Not the over-the-top crap that people normally write (well, Wick was a nut job...a well-written one). The action scenes were well played out, drawing you in. Just enough detail, like with the confrontation with Coburn.
To the author, please consider getting a professional cover done. The current one really doesn't do justice to the level of writing in this book. (Update: the book cover was changed.)