The film drifts between unpretentious intimacy and cliched superficiality, and is much the lesser for the latter. Schock is not an intrusive filmmaker, but he still adorns the movie with trademarks of intrusive filmmakers (such as using too many captions and holding the film to a strict arc), and the film gets somewhat lost in that contradiction. Along with this misstep, Schock also doesn't keep a long enough focus on certain elements (such as the actual circus performing), and jumps around too much, showing us things not entirely related to the plot and giving us the same information again and again.
I hope that Schock gets his content flaws down before his next outing, because if he does, he may be a strong documentarian. But even though "Circo" has some good insight, it didn't grip me and as a result I was waiting impatiently for its conclusion. C+