I'm in the same camp. That documentary - as incomplete as it was - made my dad cry.
One of the hardest things to realize is that Bergen-Belsen was a mere "concentration camp" that held political prisoners as well as Jews, Gypsies, and others the Nazis hatted. In terms of volumes of dead, it was very small as compared to the "extermination camps" dedicated to killing.
Auschwitz-Birkenau, Blzec, Chelmo, Treblinka, Maly Trostinets - all conveniently set up OUTSIDE Germany (mostly Poland) was where was systematic murder in mega-death numbers took place.
Ann Frank died in Belsen.