Lut's complaint about this book, back before I started my re-read of the series, was that the Captain Ivan Vorpatril of the title is nicknamed "Ivan the Idiot" by not only Miles, but many of his relations and acquaintences. Lut felt that, accordingly, Ivan came across as inconsistent in this book by being too clever. My own feeling was that Ivan's intelligence was unfairly maligned in by the moniker -- that Ivan had never been an idiot.
So I was paying close attention to Ivan's appearances in earlier books, and my sense on this front was only strengthened. In the first book, Ivan does show a very high level of cluelessness -- but not so much 'idiocy' as a lack of savvy and perception. Even so, it's he and not Miles that twigs to the key problem back home with Miles current behavior in the depths of space.
In general, Ivan is often annoying: he'll dodge out of obligations if he can, he whines about the ones he can't, and one of his frequent laments is "It's not my fault." But in fairness, it hardly ever is his fault. He is the designated damsel-in-distress: at least twice (not counting this book, he's kidnapped, mainly because some plot of Miles's has gone wrong. Not because Ivan himself did anything stupid. In fact, generally the most foolish and crazy things Ivan ever does are because someone else roped him into it. You get the sense that Ivan's evasion of his relations is 90% self-defense. Talking to them is dangerous. Literally!
And I got the very strong sense that Miles was not a reliable narrator when it came to Ivan. Ivan and Miles are same-age cousins who grew up together, but Ivan is tall, strong, fit, handsome -- everything Miles isn't, physically. But Miles is brilliant, persuasive, and focused, while Ivan is indolent and easily browbeaten. Miles, moreover, has a lot invested in being smarter than Ivan. It's the one area he can top his good-looking, popular cousin, and Miles is relentless in insisting that he does. Ivan's own comparative lack of ambition and strong desire to avoid politics gives Ivan himself incentive to play down his intelligence. Ivan doesn't want to get a lot of credit. The reward for a job well done is more jobs. But if you look at his actual actions and not what Ivan says, Ivan's shown to be bright-but-not-brilliant, loyal to a fault, and actually makes a concerted effort to follow rules and stay out of trouble, when people aren't coercing him to do otherwise.
This makes Ivan an unusual and charming protagonist, from my perspective. The typical modern protagonist is someone dedicated to their work, whatever that work is. You don't get too many protagonists who are unambitious and lazy. In CVA, you get two of them. It's delightful.
CVA is one part action/adventure and one part romance: the romance angle is no doubt part of why I enjoyed it so much. There's a fair bit of screwball antics reminiscent of early Miles books, except that it's all perpetrated by people around the protagonists while the protagonists are sucked along, doing their best at damage control along the way. The change of view and priorities there also amused me.
This is not a good entry point for the series -- about half the book is occupied by appearances of old characters and catching up on them, which is great when you know and love them but would lose its charm if this is the first time you met them. Well worth the read if you know the series, though.