Let me get the bad out of the way first, James Hanlon is absolutely terrible trying to act his descriptions of what was going on with the rookie training and events of the day. Really it is in stark contract to the other fire fighters without acting aspirations who are natural in their delivery.
That said it is an amazing film that is impossible to watch without tears in my eyes. I am an English guy from London but I love New York and have visited many many times before and after September 11th. It is a second home to me and I can't help but feel devastated at the loss of life but also the destruction of part of such an amazing beautiful city. This is the real deal, in with the fire fighters with everything collapsing around them. I am so glad the footage exists to show people how it was on the day. It is a shame that they didn't use any footage of people jumping from the buildings because friends who were there tell me this is such a major part of their memory, it should be included to show future generations just how terrible it really was.
Conspiracy theorists can go to hell by the way.