When I first looked at this book I was pretty skeptical. One because none of the authors are BYU professors of religion or General Authorities. That sounds a little harsh but a person who has a BA or MD in business or whatever is not as creditable as those who study religion as a profession or are General Authorities who are taught by the 12.
I have not read the whole thing but a few pages. I unfortunately found an error in the book. It was regarding Joseph Smith's last dream. They claim that the dream Joseph had in Iowa, recorded by W. W. Phelps, was his last dream. However, it was not. In Carthage Jail, Joseph had a dream on June 26, 1844, the last night of his life. He was killed the next day, June 27. The Prophet Joseph stated, "I was back in Kirtland, Ohio, and thought I would take a walk out by myself, and view my old farm, which I found grown up with weeds and brambles, and altogether bearing evidence of neglect and want of culture I went into the barn, which I found without floor or doors, with the weather boarding off, and was altogether in keeping with the farm. While I viewed the desolation around me, and was contemplating how it might be recovered from the curse upon it,there came rushing into the barn a company of furious men, who commenced to pick a quarrel with me. The leader of the party ordered me to leave the barn and farm, stating it was none of mine, and that I must give up all hope of ever possessing it.I told him the farm was given me by the Church, and although I had not had any use of it for some time back, still I had not sold it, and according to righteous principles it belonged to me or the Church. He then grew furious and began to rail upon me,and threaten me, and said it never did belong to me nor to the Church. Ithen told him that I did not think it worth contending about, that I had no desire to live upon it in its present state,and if he thought he had a better right I would not quarrel with him about it but leave; but my assurance that I would not trouble him at present did not seem to satisfy him, as he seemed determined to quarrel with me, and threatened me with destruction of my body. While he was thus engaged, pouring out his bitter words upon me, arabble rushed in and nearly filled the barn, drew out their knives, and began to quarrel among themselves for the premises, and for a moment forgot me, at which time I took the opportunity to walk out of the barn about up to my ankles in mud. When I was a little distance from the barn, I heard them screeching and screaming in a very distressed manner, as it appeared they had engaged in a general fight with their knives. While they were thus engaged, the dream or vision ended" (Joseph Smith, History of the Church, 6:609–10, bold & italics added).
I would just be careful in taking some of their claims as facts considering I only looked at 5 pages and already came across a mistake.