My favourite press review of the documentary is from Robert Lloyd of the Los Angeles Times:
It's a long and at times slow film that some viewers will undoubtedly find tedious and frustrating, though I would count its length and pace among its virtues. … [B]y taking its time, it sensitizes you to nuance, until the smallest most awkward stabs at connection or expression become terribly moving. …
If there is a message to extract, it might be that every kid needs a sympathetic adult in his life, but I think that's almost an incidental point. I'm not sure Sutherland has a point, beyond awakening a feeling of common humanity in his viewers, and I can't image a better one. Insofar as any edited work can be executed nonjudgmentally, this comes close to that ideal. It's a rare thing on television, such passionate dispassion -- but then, it's a rare thing anywhere.
There is also an excellent backgrounder on the pbs website about poverty in America.