Spoto posseses an enormous amount of knowledge about the director's films, yet he transgresses in his biography by misquoting sources and casting Hitch in a very unfavorable light. Thanks to Spoto's errors and sensationalism, many people continue to think Hitch was much more deviant than is likely.
Dark Side of Genius puts Spoto in the class of celeb biographer/"sinsationalist" Kitty Kelly -- and I mean no insult to K. Kelly, who, at least, has the honesty to own up to her profession as a scandal-monger.
Nevertheless, I have found that Spoto's other Hitch book, The Art of Alfred Hitchcock, is a reliable overview of the themes and standard interpretations of Hitch's work -- a factual error or two notwithstanding. My modus operandi (for better or worse) is to settle in for the evening with a jar of Cabernet and Spoto's and ken Mogg's books cracked open to the title in my DVD player.There. I said it.