Rifts is a fantastic setting, but unfortunately this book does not quite live up to its name.
The original Rifts main book was a thing of beauty - it brought you right into the topic of creating a character, by far the most difficult part of starting out with Rifts as a game in general. The intervening years have seen massive growth in the game world, and certainly the Ultimate Edition reflects that - many individual sections show small refinements, and there are definitely useful additions to the core classes and gear within.
The problem, however, is that in adding all of the extra material the authors have forsaken the character-first layout. The Ultimate Edition details nearly everything in the Rifts setting prior to discussing even the rolling of attributes. It has become incredibly difficult to navigate the book now, and finding the rules that govern actual play is nigh impossible.
I am not entirely sorry I purchased this book, if only for the extra material, but I don't think the Rifts newcomer should spend the extra money when the original main book is so much easier and more enjoyable to use.
[2 of 5 Stars!]