This book is odd for sure, and it's not an easy read. I have to agree with other reviewers that Briony has the strangeness of Merricat in [b:We Have Always Lived in the Castle|89724|We Have Always Lived in the Castle|Shirley Jackson|http://d.gr-assets.com/books/1311400048s/89724.jpg|847007], and her narration is odd, confusing, quick-witted, entertaining, melodic and completely unlike anything else I've read. I'm avoiding the word "quirky" here because I feel that that word is given to describe something that is different, but in an "oh, that's adorable!" way, and Briony is different in an "oh, you're really really weird, but in a sharp and fascinating way."
You'll either like this book, or you won't. I started liking the strangeness, got a little meh'd in the middle when I wasn't sure where the story was going (the story mixes between being mystery-driven, romance-driven, and daily-life-driven), and then liked it when it picked up more towards the end. It's one that I have to reread soon, and I feel like once I'm not frustrated by the mystery and jumpy narrating, I can sit back and enjoy it a lot more. Briony and Rose have the best lines!
Briony's relationship with Eldric reminded me a bit of Ella and Char in [b:Ella Enchanted|24337|Ella Enchanted|Gail Carson Levine|http://d.gr-assets.com/books/1338459167s/24337.jpg|2485462]. They can act like such kids together, it's cute.
Overall, I liked this book on the first read, but I can see it getting better each time I revisit it.