First impression: Another strong female protagonist who has discovered she has superpowers, has accepted herself despite the mistakes she made, and must make a crucial decision to save someone/thing that will most likely destroy a city and lead to the death of some people. Oh yea, and there is a cool guy following her, with his own problems, but he'll support her no matter what, even if they fight a lot, and they'll love each other forever.
Second impression: The strong female protagonist is a powerful figure in a well-established fantasy world, and her boy is a strong character in his own right.
This is a great finale to an epic fantasy series for teens. It is very well-written, the characters are strong and stand on their own, the magic and lore of the world is fascinating. I would highly recommend it to fantasy fans. However, the Wintercraft series is not for the casual reader. It can be a bit dry, with lengthy descriptions and long musings into politics and history.