I found this a very good book which described the life and times of the Marquis de Sade succinctly enough to leave you time to do other things with your day, but not so succinctly that you felt you were missing out on information. However, I did find this book quite subjective to read - the author imposes his opinion on de Sade's life quite often, meaning that you can't always be certain of the manner in which something was said. Other than that, it's a very good book.
This book gives an excellent brief yet still detailed account of the life and times of The Marquis and his famous (or infamous) books. The Author also points out that Justine etc. were only part of a vast amount of work de Sade produced which included fiction, non-fiction, plays and pamphlets. His opinions are very subjective and this muddies the account somewhat as the reader has constantly have to form an opinion of an opinion. Penetrating de Sade's mind is probably a futile exercise anyway. The book is marred at times by psychobabble: whenever I hear 'Freud says', I reach for the off switch. Well worth reading however for those who want to learn more about the man and his time as well as by - and especially by - those who have already formed an opinion while knowing nothing about the subject.