This is not a proper book review. If you want to know more about the book, I've linked to the author's webpage at the start of this entry. Moving on...
There's a lot to like about Finnikin. Evanjalin -- a main character whose POV we never get in the book -- is one of the more kickass women I've read, and we all know how much I love a strong female lead. There aren't any overtly Crowning Moments of Awesome (not like a certain Cordelia Naismith I've also read recently - oh my, so much to fangirl over <3), but the way she's manipulated people and events into falling into place around her throughout the book (with a little divine assistance), leaves no doubt as to who is really in charge -- titular Finnikin's character arc notwithstanding.
I suppose I like the characters in Finnikin, but not as much I'd liked them in Jellicoe Road. Maybe having an overarching plot inevitably detracts away from character development, as opposed to a book in which nothing happens much of the time. If so, Finnikin should make up for it with its setting. But it doesn't. The worldbuilding in it is nothing spectacular. In fact, the kingdom of Lumatere initially reads like a classic fairy tale with its black-and-white morality and its perfect rulers and perfect inhabitants. It's as if Marchetta then came along with this thought experiment: 'What is the worst possible thing I could have happen to these people?' And thus Finnikin was born.
So the world of Finnikin came off to me reminiscent of the Grimm tales in its setting and atmosphere, except it's...well, grimmer. I feel that Marchetta only really used the fantasy setting as a backdrop, to spur her what-if scenario. Hence, while it was a pretty good read, I cannot commend Finnikin of the Rock as a fantasy novel. I definitely think it better than a lot of the (admittedly little) YA I've read, but even then it loses out to her other books.