And here we are one month later and I'd have to say the same thing. LOL While I like THC and HI, they do tend to get pretty repetitive. They are not in depth analyses (even when the topic is historical) but hey, it's entertaining. I think they can be informative but as others have said, if you are looking for probing, factual history, you need to look elsewhere.
While many documentaries are written by scholars/academicians, most are written by TV writers who look up academic material and base their program in them. While they are based on facts and/or scientific data, documentary writers do tend to misinterpret the meaning of those data. In terms of historical documentaries, I have seen many writers state popular "facts" or myths rather than what actually happened as stated by historians. Documentaries are mostly for the common viewer who's interested in some basic information about a certain subject. The exception of the rule may be... documentaries that are written and presented by certain scientist/historian/academic themselves, since it is their personal interpretation of facts that they studied for years. But remember that they could be wrong, too. Plus documentaries have the limitation of having to put relevant information inside a certain timeframe and has to be accessible to the common viewer who possibly has no previous knowledge of a certain subject but shows interest in it. For those who really show a serious inclination to study something, there is no substitute as the venerable book.