My quick hits: Completely engrossing narrative on five years of Iraq that includes interviews with nearly everyone but Bush, Cheney and Rice. A lot of interview and press conference footage was used to get their statements from throughout the period.
I guess the biggest conclusion I had was over the complete tragedy that resulted entirely from Bush's lack of leadership and the situation that is created from essentially pitting higher ups (Rumsfeld, Cheney, Powell, Rice, Wolfowitz, Bremer, etc.) against each other. With guys like Rumsfeld in desperate need of defining some kind of legacy for himself, you had others like Powell and Rice forced to dig in instead of working toward consensus. I'm not talking about compromise, I mean the inability of all players to set aside their own (significant) baggage in order to do what's best for the country.
I can deal with policy and even political differences, but when all the evidence is laid out like it was on Frontline, what sticks out most is the continued inability of the Bush White House to function as a team. I found myself siding, over and over again, with people like McCain, Powell, Armitage and even Rice who, more than anything, were routinely astonished at how Rumsfeld and Cheney got their way.