I watched DVD 1 only. The program proper may have 10 minutes of good information; otherwise it's snotty putdowns of religious people. It's as if director Brian Flemming only recently discovered both atheism and sarcasm, and feels with these tools he can easily bludgeon his opposition.
Also, Flemming wanders extensively into his own personal issues, and they take over the movie. It never gets back on topic.
Religious people are prone to discount skeptics when their objections to religion are obviously rooted in abusive upbringings. Arguments from such victimized people seem irrational, and therefore unconvincing.
Anti-religious people will want more data. We don't need to be told that religious people are nutty, any more than American Jews need to be told how annoying Christmas music gets by mid-December.
In the best scene, the Superintendent of Fleming's childhood Christian school rather insightfully confronts the director on his motivations. That seems like the most honest part of the movie, and it was too short.
If Fleming were a bit more self-aware, he might have a good story in him about his own (past & current) relationship to Christianity, and the abusive institutions that indoctrinated him in his youth.
And perhaps he could lend his "Christ never walked the earth" material to a more serious documentarian. I'm not studying the writings of Saul/Paul to find out how air-tight this all is, but a quick browse of Wikipedia suggests most of these arguments are discredited.
The bonus interviews are pretty good, tho they don't bolster Fleming's thesis much. Sam Harris is a good spokesperson for the anti-religious POV, and he doesn't go light on those other, non-Christian religions. Harris also has some good (and easily Google'd) interviews on Salon.com , Amazon.com , and Samharris.org .