When I went to borrow this book, the librarian who checked it out for me said that she'd read it, but "didn't like where the magic came from." I had no idea what she meant, but when I started the book and figured it out, I actually thought that having the different powers come from different metals was a pretty cool idea - if somewhat problematic if you think too hard about things like earrings and whatever, although that was explained somehow. Either way, I tend not to think too hard about things like that so it was all good.
I did enjoy this book, although that is not the same as saying I will now go and seek out all the books that claim to be similar. I remember that I finished it and really wanted to know what happened in the next books - without having to actually to read it. I need the TL;DR version.
There is a lot of religion stuff in there, which I find fascinating if done in the right way. And it was interesting here, in a 'I wonder where it's going with that' sense.
I don't KNOW why I didn't like this book more. It did have cool characters, it did have strong female protagonists (Luke knows what I like), and I do want to know what happens next. I'm just hard to please, I think.