I tend to lean towards The Observer. The acting (Phoenix and Hoffman) is brilliant but I found myself wondering at the motivation of the director (Anderson). The treatment of the cult is predictably based on sex, money, power, neediness and charisma. The personality of the Master has been replicated in real life a thousand times over. So we are left with the Addict (Freddy Quell, played by Joachim Phoenix). I reckon it's really his film, and it should have been called "The Tormented".
The rest of it is an overlong pastiche, confronting and desperately taut - and engrossing in parts - but as a 'whole', the film falls short. That's my two-bob's worth. Other opinions?