I know it from my exchange to America and I really enjoyed it. There are many historical documentaries over here too, but no channel where they are aired all the time. Of course one must be a bit careful about some documentaries. While some are just doing an excellent job in presenting history in an interesting and entertaining manner there are also some which are just too sensationalized and emotional to be regarded objective science (over here there is a producer of documentaries by the name of Guido Knopp. His documentaries are very popular and viewed by many, but they are presented in such a yellow press type of manner that some of our Profs at the university are talking of the "Guido Knoppisierung" (Guido Knoppisation) of historical science).
I've seen quite a few American documentaries as well. "Liberty! - The American Revolution" for example was really interesting to watch. They came up with a great mixture of reenactment and lecture. They had their facts right too and presented the perspective of both parties in the revolution having actors dressed as their historical counterparts and quoting the historical characters. A Hessian soldier in that documentary actually talked in an old fashioned form of German with English subtitles.
However, in spite of all that I'm uncertain if the documentary would be regarded as "objective" (it is usually agreed that perfect objectivity is impossible to reach in historical discourse so objective in this context means "as objective as we can get") the music in that documentary sure does a lot to keep you focused, but it does also a lot to make you jump up grab the Pennsylvania rifle from the wall in your bedroom and shoot up some of those redcoats or rebells
In that sense the documentary has a rousing effect similar to that of some non documentary movies. There is no real agreement on whether or not that is "acceptable" in scientific material. Personally I tend to think it is to some degree acceptable so long the documentary does stick to the facts and does not glorify or demonize one party. I'm afraid if one cut out all music, and cut out everything that was not strictly scientific a documentary might easily become drowsy rather than educational.
From what a former history teacher of mine said many German historians tend to be "too picky" they wouldn't dare constructing a model of an an ancient town fearing that the roof tiles of one of the 567 buildings in the model might have had a different color in reality. On the other hand he said that some of the historians in England and America would construct a whole ancient town based on the fining of a single roof tile without any knowledge about how many buildings there were anyway.
I think the best way is somewhere in between. As accurate and non-speculative as possible, but not to the point where it really blocks the process of historical research.
