Having taken several tries to actually get into Bujold, I'm now very much enjoying working my way through the Vorkosigan saga; so far, they've all been enjoyable and entertaining and comforting without being fluffy. They may have many of the trappings of standard military SF, but they're really character-driven novels whose military setting is almost incidental. Bujold's characters are delightful and well-rounded, likeable but realistically flawed and sometimes exasperating; in this novel, Miles is continuing to grow and learn from his experience and his fairly frequent mistakes and misjudgements (despite an amazing talent for turning every situation to his advantage he is clearly very young, very inexperienced, and far from perfect), and I particularly loved Gregor, the young Emperor of Barrayar, resenting the weight of the crown he has worn since early childhood and trying to work out who he is and how to be his own person within the limitations of his role. The exploration of what makes a leader, and what it means to be Vor - a member of Barrayar's hereditary military/aristocratic class - is a big part of what makes these books not-fluff for me; they may be fun, but they're also interesting and thought-provoking.
I note that The Vor Game won the Best Novel Hugo*, which surprised me a little, as although I enjoyed it a lot the plotting isn't terribly tight and it doesn't have the "doing something new and interesting" feel I tend to expect from Hugo winners (even if "new and interesting" in 1990 was rather different from "new and interesting" now, it isn't doing anything very different from The Warrior's Apprentice). It's still great fun, though, and probably more enjoyable than many "new and interesting" but more serious books.
*"at the time when good writing and plot were more important than political leaning", says one Goodreaders reviewer, who has clearly failed to spot that the novel has a disabled protagonist, at least two prominent LGBT characters (to be fair, Aral's bisexuality is pretty much blink-and-you'll-miss-it, but Bel Thorne isn't) and more than one woman in typically male command roles.