I've been making my way through Baen's stable of military sci-fi authors recently, and most recently I picked up Freehold (admittedly, with the help of the author, Michael Z. Williamson, who happens to be a Schlock fan).
If you're not bent like a libertarian, you'll probably feel like you're being preached to for much of the novel. While it's ostensibly the story of an Earth expatriate moving to an outlying colony and then helping those "backwards colonists" (who are pretty progressive when you get right down to it) fight off an invasion from Earth, the author spends a LOT of time explaining why the political system on Grainne is so superior to the top-heavy systems we're all more familiar with. There's a definite utopian feel to things.
The chief problem with this sort of approach is that all the arguments you see marshalled AGAINST the political system described are essentially straw-men. They're set up to be knocked down, and because they take place in a fictional universe, you're stuck wondering what would REALLY happen with this sort of a government. All this means, though, is that as a political treatise the book can't really be taken too seriously. That's NOT to say that it doesn't do a good job of identifying some things that are wrong with our current political system, however.
Politics aside, it's a darn good read. And even WITHOUT pushing the politics aside, it's pretty enjoyable. It's a lot longer than I was expecting -- a savvy editor might have chopped it into three books, adding a bit more adventure to the first and second acts, and then leaving the climactic third act all to itself in a third book. Then again, a savvy editor will take a debut work from a new author and send it out into the wild to stand alone, rather than chancing the additional overhead on a trilogy.
The military action in the book is first-rate. I've been, as I said earlier, plowing through stuff from David Weber, David Drake, John Ringo, and others, and Michael Z. Williamson can hold his own with those guys just fine. The characters are compelling, and the protagonist is genuinely interesting as a person, and it doesn't hurt that she figures out how to kick several different flavors of butt through the course of the book.
If you can't stand libertarian politics, though, you'll just come away from this book pissed off -- unless you're open-minded enough not to get upset when the fiction you're reading challenges your worldview.