I've read some discussions on imdb about the film, and although I initially wasn't interested in watching a film that dramatizes the 9/11 events (Michael Moore's Fahrenheit 9/11 was disappointing to say the least, and Spike Lee's 25th Hour says it all for me), after following the discussion and reading some interesting reviews (e.g. Film Comment) I changed my mind. 

The interesting thing about differing opinions on this film is that one side seems to see it "devoid of humanity" (as you put it) and lacking an honest emotional impact, while the other side claims it is the best account of these events so far, and an incredibly moving experience.

I believe wpqx is an advocate of the film, so it would be interesting to read his opinion.