My full review is here on my personal website. I'll post a few excerpts here, though:

4.5 out of 5.0 stars

The very worst thing about this book is that we miss all of Sabriel’s lessons. She already has a better than basic grasp of her skills and what she has to do, so to some extent seems like she can do everything because of destiny or fate. Her schooling is addressed in the book where it mentions that she did learn things, but it never has the main focus of our attention.

The very best thing about this book is Mogget! Mogget is incredibly awesome, but I can’t say anything other than he’s a cat or I would give away spoilers. o_O