I say this with great caution, as I hate it when people self-righteously declare an authors work to be unskillful or amateurish, when I find the book to brilliant. BUT... having read this book right after reading an Isobelle Carmody book (a woman with a very different style of writing), that is how I found it. The prose felt clunky and the constant clichéd glass and storm metaphors made me want to roll my eyes. Gah! The characters seemed predictable and unimaginative... I really felt like it was poor in comparison to the Study series and especially to Inside Out. MUCH better books.
Opal didn't strike me as a particularly well defined heroine and I did find some elements of her magic unbelievable, though they may be explained better in later books.
However, after saying all that, this was a nice easy read. The plot was more than entertaining, fast-moving and capturing. I'll probably get the rest of the books out at the library in the hopes that they get better, but knowing that even if they don't I'll probably still enjoy the books.