I really liked Ballad!
I was satisfied at the end, which is always a good sign. Interestingly, it wasn't the climax of the action that I found most compelling, but the decisions made by the main characters. It was nice that the climax had emotional resonance without the plot having to revolve around the Total Destruction of The World. This is definitely a character-driven story.
While the conclusion didn't blindside me, a little more foreshadowing would have made the end feel inevitable once all the threads came together. But I think some readers will argue that I'm being nitpicky on that point.
There's enough description to set the scene, but dialogue pulls things along at a quick pace. There's a nice balance between the character's internal thoughts and the external world, which I think can be difficult to find in first person narration (cough, Twilight, cough).
I also liked the adult characters, who were reasonably flawed but often had their hearts in the right place. Sometimes they were even useful unlike in some other YA lit (cough, Harry Potter, cough) in which the author makes the adults completely useless so that the kids can take center stage.
Another thing I liked was how gender was handled. There were characters who happened to be male and others who happened to be female. But it didn't define who they were or what they were capable of (something I'm sensitive about). Characters of both genders made mistakes, were strong, were weak, were emotional. You know, sort of like REAL PEOPLE.
Finally, Maggie Stiefvater must be a pretty compassionate person because all of her characters were likable. Yes, all of them. Even the not so nice ones (okay, with the exception of a very minor faerie who only appears in one scene). Even the King of the Dead was a cool guy--one of my favorite characters!
And the romantic scenes--while totally PG and appropriate for a YA audience--were totally sexy and believable!
I realize this review didn't cover any of the plot. But you know, you can read that in just about every single Amazon review (seriously, what is up with that?). This is just my breakdown of what I liked. I thought I might as well get it down on paper since I've been having conversations about it with myself in the shower.
Summary: Well written YA book about Faerie with complex mythology and likable characters. Recommended for any adult or YA into Faerie/ urban fantasy. Not a book that will haunt me or color my dreams (then again I'm at least 10 years older than the target audience...sigh) but definitely a worthwhile read.