Although the core mechanics of the World of Darkness line are (mercifully) transparent and mutable, 'WOD: Mirrors' takes the flexibility of the system to its furthest extremes. In short, almost any sort of addition or replacement to the core mechanics that you may ever (as a player or a storyteller) have wanted to see changed is probably covered somewhere in this book.
It is a fine reminder of just how much manipulation the basic mechanics can take.
Everyone will respond to different aspects of what is offered here and for the most part, readers & gamers can cherry pick the adaptions they like and ignore (or further alter) those they fine disagreeable. The book is somewhat lighter on expanding the narrative universe, however. There is some attention paid to possible alternate realities, but this section of the book feels a bit less enthusiastic then the straight mechanical alterations.
Still and all, there is much to think about here and much to test out around a gaming table.
[4 of 5 Stars!]