The personifate remind me a little of the Daemons from His Dark Materials and I would say the world-building is about as good as well! While the characters occasionally fall into stereotype (especially Cora), their relationships are endearing. 

The world-building is definitely it's strongest part: this book could've been an instant classic if the story had been just a tad sharper, a tad cleverer. I was fully expecting

Edwin to be Prue's brother since it was unclear at the beginning whether souls take their original voice and there were some plotpoints that hinted at it

I think what ended up happening was a better way to deal with the topic of grief and letting go but I was disappointed that the plottwists that did happen were only very lightly hinted at. 

The clear inspiration

(wendigoos)

behind the villainous personifate machines at the end also makes me take my rating down. 

That said, I did enjoy this book. It was a very comforting read and it's great to give to fantasy loving middleschool kids.