This is a very interesting documentary to watch, not only for the topic it discusses, but in discussing the very nature of scholarship, especially dealing with homosexuality.
As far as the documentary itself, its pretty well done. It covers how a heterosexual German historian tries to prove his claim that Hitler was homosexual, and, in a refreshing change in a documentary, it has other historians commenting on his findings and theories. In the end it does not really prove much, mainly owing to a dearth of evidence, and reliance on some rather dubious, and unverifiable sources. A good point of the argument revolves that any records confirming his homosexuality would have been destroyed by Hitler, so you're starting to delve into JFK-esquire conspiracies and cover-ups. One also may note that the stigma of homosexuality, with its negative connotations may be used simply to slander an individual, so any second hand accounts need to be examined in that light as well.
But the greatest point the documentary raises, and continues in its DVD extras, is the topic of scholarship and homosexuality. Because this is such a polarizing topic, and evokes strong feelings among both straight and gay historians, it becomes very clear that retaining objectivity in this field of study is very difficult. In fact, the attempt to be objective and not let personal biases, either for or against, is probably the greatest struggle of the historian. Coupled with the fact that evidence is rarely cut and dry, gaining the truth about a person's sexuality often has to go by inference and assumption, a very dangerous minefield for any historian.
The reason I gave this documentary such a high score is that it really makes you think. By having gay and straight historians, with proponents and detractors on the theory on both sides give voice, it really is one of the few documentaries that lets the viewer draw his own conclusions. The DVD extras which then discuss the very process of such scholarship further challenges the viewer to re-examine the very conclusions they just drew after the documentary's conclusion. A very highly recommended view for people with an interest in history and scholarship.