I have mixed feelings on this book. It is very interesting and well-written. If I was reviewing it as fiction, it would be a 4-star. Maybe Irving should have gone for a career in historical fiction. He probably would have done very well and there would be no controversy surrounding his name.
The most problematic aspect, in my opinion, is the constant use of descriptors such as: "pridefully," "with biting sarcasm" "expressed his triumphant zeal" when subjects in the book are speaking or thinking. He included a lot of detailed thoughts and tiny actions, such as 'he permitted himself a contented grin" when Goebbels was on a train held-up by troop carriers. "Grinning evilly' and "eyes gleaming" appear a few times. I thought there was entirely too much embellishment of emotions, motivations, and demeanor for a non-fiction publication. The author couldn't possibly know how these people thought, spoke, and acted in such minute detail on so many occasions. Goebbels diary explains his thoughts and the author did cite many entries, but he added quite a bit of detail he couldn't have acquired from reading anything. Nothing is impossible, but there aren't many written sources that include detailed descriptions of thoughts, habits, gestures, tone of voice, and demeanor of participants in an event or conversation.
I've read so much about this period in history that I learned to read German because quite a bit of material (documents, memoirs, letters, etc) wasn't translated into English. Its also possible that I just couldn't locate English translations, but the problem was solved by learning the language. I don't consider myself fluent and I'm still learning, but learning German wasn't as hard as I anticipated. I don't know if I picked up German language concepts and terms from reading so much about the WW2 era and pre/post war years or if German really is the closest language to English. I've tried to learn Russian too, and that is an entirely different story. Its much more difficult.
I also read 'denier' literature. I am not a Holocaust denier by any means, but I don't view literature written by deniers as dangerous. I have enough confidence in my own knowledge to read content I don't agree with, and I firmly believe that censorship and banning books will backfire and give deniers more legitimacy in some circles, along the lines of "See, we told you 'they' don't want you to know this.' Banning books makes it seem like there is something to hide.
There are always discrepancies in historical accounts. I noticed several accounts in this biography that differ significantly from descriptions of the same events in other sources. I didn't notice anything that could be classified as 'denial' in this book though. Irving made several references to Jews. He didn't make any anti-Holocaust claims, although he didn't go into detail on the treatment and eventual fate of the Jews either. On the positive side, I did come across two events that I had never heard of before and researched those specific incidents on my own after I finished reading. Other sources I was able to find were in agreement with Irving, and I was quite happy to learn something completely new.
I would recommend this book to anyone with an interest in this period in history, but no one should read just one account of anything. There's an amazing amount of literature concerning WW2, Nazi Germany, and everything related to that era. Its impossible to learn too much. I think this biography has value as long as everything in it isn't taken as unassailable fact.