There aren't a lot of reasons to read this book except to address the nagging feeling - a feeling shared by many people - that Mel Gibson is a lot more unpleasantly crazy than the occasional leaked tapes and police reports suggest.
On that front, "Heaven and Mel" is absolutely everything you could want; a portrait of a desperate, disturbed, dangerous Hollywood burn out in all his ranting, racist, capricious, petulant, aggressive non-glory.
Unfortunately, this is a portrait painted by Joe Esterhaz, a man who comes off as a spoiled Hollywood hack in his own right. From the opening lines about Joe finding God (conveniently after getting throat cancer) to his staggeringly arrogant belief that God or any other Catholic entity actually cares which movie gets made and by whom, Esterhaz manages to feel detached from reality in a distinctly showbiz way.
As such, whilst the schaudenfraude desire to hear juicy gossip about Gibson is fulfilled in spades, the man dishing the dirt never comes off as overly likeable or normal. As an audience, we may be shocked by Mel Gibson's raging, spittle-flecked race hate, misogyny and oddball religious mania, but we also never quite empathise with our narrator.
In summation, if even ten per cent of Esterhaz's allegations are accurate, then Gibson is a hateful, crazy monster. It's just a shame he's a monster being outed by a blowhard.