This book was a catalyst for me learning some pretty scary things about our religion. Some of the claims are far reaching, but almost all of the data is corroborated by LDS historians and non-LDS historians. There are tons of things that we are not taught as LDS folk, and tons of things that we are purposely isolated from in church.
This book was a catalyst for me losing my faith. Having said that, I would rather have the truth then a testimony based on lies.
By the way - aside from the earthshattering things about early church history - it is a great read into the mind of the Lafferty brothers.