Keep this in mind. This was a forum in (1) Orange County, CA (Very, very Republican), which is home to John Wayne Airport, (2) before an Evangelical Right audience, and (3) with questions asked by an Evangelical Right pastor. In all honesty, I think he was pretty fair given his views. Now, I think Obama did just fine. He looked authentic, and he went in to a RW crib, and held his own. Even better, he just had Rick Warren, a pastor, vouch for his Christianess. If Obama mooned the audience, but Rick Warren vouched for his Christianess, that alone would have made it worth it.
As for McCain, he was literally preaching to the choir. Yes, in reciting his stump speech, he looked polished, but that was because there was no thinking involved. No analysis. Evil, abortion, tax cuts and Russians are bad. It was a very Cro-Magnon performance.
HOWEVER, consider how McCain and Obama would have done in a town hall meeting before union members with questions being posed by the President of the AFL-CIO? I have a feeling that Obama would just be cheerfully reciting his talking points, while McCain would be squirming his ass off, particularly in response to the what is rich questions and class warfare responses.
Here is CNN's story:
http://www.cnn.com/2008/POLITICS/08/16/warren.forum/index.html