It does not touch the side issues that really are the staples of modern politics. While Hillary Clinton and Barrack Obama are repeatedly attacked such as the heavy reliance on sermons by Reverend Wright, relatively little mention is made of John McCain's personal life such as his first marriagne to Carol McCain, a former model who was disfigured in an accident, and whom McCain abandoned for heiress Cindy. The is similar to Newt Gingrich. The other thing that is not examined is that John McCain was estranged from his children with his first wife who refused to attend his wedding with Cindy.
For example, consider this article by the Boston Globe that just skirts around the issues of John's first marriage, and his children from his first marriage. Notice there is no mention of the wedding. So, Free Ride, to its credit focuses more on substance, but it also gives John McCain a free ride by glossing over some of his personal skeletons.
http://www.boston.com/news/nation/articles/2007/12/27/mccains_children_avoid_the_limelight/Also, this article discusses Carol in a little more detail. Again, John will probably just attack any media outlet that pries into this, and the media will back off. However, neither Barrack Obama nor Hillary Clinton enjoy any such deference.
http://archive.salon.com/mwt/feature/2000/03/06/carol/index.html