I quite liked Trudi Canavan's first (Black Magicians) series, though I know some found it overly romantic. Her second trilogy (Age of Five) was less compelling, and I skipped the third (Traitor Spy) completely.
In this latest offering, the first in the Millennium's Rule trilogy, Canavan treads familiar ground. Very familiar; in fact the first book has a very formulaic feel to it. Young people, oppression, misunderstanding, romance. The writing is generally quite good, but there are very few surprises in this novel. It's been slightly updated to include a nod to steampunk, and slightly more sex, but otherwise, it's ground we (and Ms. Canavan) have trodden before. Even the societal pressures (girls must marry, raise children, not speak; creative types are poor but happy) are from some decades back.
The book is further weakened by a particularly limp magic system. Not everyone can (or should) be Brandon Sanderson, with a painstakingly (sometimes painfully) logical mechanism for magic. But, aside from an interesting innovation on depletion and creation of magic (inconsistently applied), Canavan doesn't even do much hand-waving. It's the kind of magic where you just exert your will and things happen. That can be fine as well, but when magic is easy, there must be limitations or consequences. Here, there are social barriers, but few magical rules. There's a strong feeling that the rules are at the convenience of the author, rather than having any kind of internal logic. Some of the non-magic elements were equally non-credible or inconsistent. It makes for disappointing and unfulfilling reading.
These limitations are a shame, because otherwise, Canavan is generally a good writer (leaving aside some awkward infodumps). The characters are (within their tired settings) interesting, and the story ends with plenty of things that call for exploration. If Canavan had taken the time to try for something a little fresher, the story could have been very good. As it is, it's a decent but not compelling entry in the generic fantasy ranks; one that suggests Canavan either hasn't grown as an author, or isn't really trying.