Duane does what she likes to do, which is take a cheesy SF setting and put honest-to-serious human beings in it. (See also, her Trek novels.) Cmdr Jonelle Barrett runs an X-COM defense base -- she runs it well. This means paying attention to logistics and budgeting. (True to the game mechanics!) Then trouble arrives, and the book alternates between air assaults, ground assaults, and tourism in Swiss villages. The tourism is the best part, and yes, it is relevant to the plot. I'd say this was intensively researched, except that the research obviously consisted of going on Swiss vacations as often as humanly possible, and I suspect Duane was doing that anyhow. (According to her blog, as I write this, she's wandering around the Breisgau.)
There are Swiss cattle farmers. You know how aliens like to abduct and mutilate cattle? The author has fun with this.
It doesn't add up to much -- it feels like a pilot episode to a series that never materialized -- but if you're a Duane completist it's worth grabbing. Except you probably can't find it; the rights are owned by Microprose and I'm sure they're buried in a box somewhere. Sigh.