This book is academic but approachable. At times you may need to keep concentration levels up, a few things just went over my head(though I think that's just down to my mind being nearly 7 years out of practice in academic reading in UNI rather than the content being difficult)
It's a very concise and thorough review of the concept and history of heresy. The only thing that makes me not give this a 5 star if that i feel it would have been beneficial to delve in the Roman church more, from the reformation onwards. To me, this would have wrapped up the entire concept neatly as it would have confirmed and consolidated his theory that he consistently makes throughout the book that the meaning of heresy has changed over time from a development of ideas that were termed 'heretical' to a word that was used as an excuse to power and control rather than theological grounding.
Other than that however, a fantastic read. Recommend.