I enjoyed this book. Before I get into the review, I want to make some general comments.
On some of the hoopla surrounding this book
There is an enormous gap between Catholicism and Christianity, if you base Christianity on the Gospels or anything else in the New Testament. That's not "an opinion." Just start reading and comparing. It's also helpful to remember that Martin Luther--a Doctor of Divinity and Biblical scholar--sought to reform the Catholic Church to principles of Christianity back in the 1500s. The two religions are fundamentally and diametrically opposed. Luther exposed the Catholic Church for the fraud it was, over half a millennia ago. And yet it's still going strong today. So, no book is a threat to Catholicism.
This book isn't a threat to Judaism, which is more a hereditary religion than one based on conversion.
Nor is this book a threat to "Literal Bible Christianity." Yes, it sheds credible doubt on many of the key Biblical concepts--such as the resurrection. However, it has long been beyond doubt that the Bible was concocted many decades after the Apostles died--and is thus full of errors (or, as many scholars hold, fraud). So, the "Literal Bible" folks already live with delusions. They aren't going to be swayed by even more evidence piled on what is already before them.
Would this book be a threat to other Christians? Probably not. Most Christian groups have officially come to terms with the errors, inconsistencies, and deficiencies of the Bible. That's why they don't take it literally. They take from the Bible and from tradition the core concepts on which they build their religious system. They have a faith that sustains them and through which they help make the world a better place. They don't pretend that their faith is based on knowledge, they know it's based on faith. So, they aren't threatened by research that provides even more evidence of fraud in the Bible.
If Jesus had survived the crucifixion, rather than having died and being resurrected, would these people live any differently? My guess is most Christians are far more inspired by the central message Jesus gave rather than the messages imputed to him long after his ministry concluded.
Conclusion: This book will not change the face of religions that claim to be Christian in nature.
On the Dan Brown controversy
Brown lied to the readers. That's what a novelist does. Brown's book, while entertaining and a source of millions of dollars of income for the author, isn't history. It's fiction. The fact that Brown pretended to present fact does rankle many people, and it certainly rankled Baigent and other scholarly types.
The dispute between Brown and Baigent has nothing to do with this book. That dispute has to do with an earlier Baigent work. And the decision in that dispute basically says Brown is a novelist (fiction, by definition) and Baigent is a researcher (fact, by definition). Plagiarism is not an issue because the works are inherently so different. Where Baigent and others are correct is in their claims that Brown made incorrect claims in his book. But Brown can legitimately do that because he wrote a work of fiction. If Brown had written a research piece, then we could all get upset and make him play by the rules of published research. If you simply remember that Brown is telling a story and not teaching a class, the controversy (as stated) is moot.
I like Baigent's approach. He gives extensive background information, so the reader gets a feel for how he arrived at his thesis that Jesus survived the crucifixion. He also provides us with insight as to why the crucifixion story, if false, would have come to be in the first place. That insight fits well into the current literature from others in this field of historical religious studies.
Some readers may have expected a one-sided approach that clearly sets forth the thesis as fact. Such an approach is what we find when people want to convince those who already agree with them. This is not what Baigent did; he took a much more fair approach. Context is a huge factor when trying to understand Christian texts and beliefs from any given era. This is why Baigent took the time to present the context. He didn't meander, as some impatient readers claimed in other reviews, he provided the necessary context.
This book is not a novel. There isn't a plot, and there are no cliffhangers at the ends of the chapters. It's a non-fiction work produced by a researcher for the layman. Baigent could have hidden behind jargon and unexplained concepts, but he didn't. I found myself intrigued after reading the first few pages. I think Baigent did a good job of making his case. But he was also careful to present his conclusion as an alternative to consider. He did not present it as the only logical conclusion. In no way does he imply the reader has to be an idiot to disagree with him.
Baigent does not claim that the resurrection absolutely never took place. He shows the weaknesses in the claims that it did, and explains those weaknesses in historical context. He then explains what most probably did take place, and why that's probable--again, in the historical context. I found his scholarly approach appealing.
Something else I found appealing in this book was the inclusion of a large number of informative photographs. Even if you (mis)read the text by coming at it with preconceived notions, this book is worth more than its price for these photos alone. They even have good captions to go with them.
When reading this book, you have to remember that it's an examination and presentation of the research, not an opinion piece developed to defend or attack a particular dogma or belief set. Baigent does challenge the reader to examine traditional beliefs, and by necessity some particular dogmas and belief sets aren't treated kindly. That doesn't, however, diminish the value of the book. Imagine a book on plate tectonics accommodating a belief that the earth is flat--it just doesn't work. Similarly, this book can't accommodate certain ideas. It does present ideas that make sense, especially when you understand the historical context in which those ideas are presented.
If understanding is something you desire, then you will like this book. If your self worth is wrapped up in holding to a particular belief set, then you probably won't like this book.