This was my problem with it: Stephen King.
Most every problem I had with this was the writing and it followed the book pretty closely. Some of this, especially in the last act, seems very silly or under developed which is a problem I had with the book.
There is one minor change I think ultimately makes the final act pretty weak. In the book, the True Knot people had basically no steam stored and continuing going after Abra because Rose is desperate. It's basically win or die as I recall. In this, it makes Rose seem stupid to confront her alone knowing how powerful Abra is.
I agree with everyone that the actors were great. Rebecca Ferguson is perfectly cast and exactly what I pictured when I read the book. How is Eean McGregor getting better looking with age? Jacob Tremblay was, as usual, the best thing in every movie he's in.
Overall, I liked this okay but it didn't wow me or anything.