Film festivals often require viewers to blurt out immediate reactions without allowing much time for contemplation before rushing off to the next screening. I had this experience yesterday, when my instincts told me to reach the verdict that a certain movie was "great" before -- upon deeper reflection aided by the insight of a colleague on Twitter [1] -- that it might not deserve the praise.

But it's a tough call. The movie in question, "Only When I Dance," offers a beautiful, immersive look at two teenage ballet dancers from Rio de Janeiro aiming to advance their careers in a fiercely competitive marketplace.

They are both tremendously talented and passionately engaged with the form. Coming from the lower class backgrounds of Brazilian shanty towns, they make ideal characters in the classic rags-to-riches tale.

Director Beadie Finzi competently plays up this angle by showing the dancers' parents as they struggle to pay the bills as their children travel to international showcases in the hopes of breaking out. In breathtakingly gorgeous scenes, dancers soar across the stage, throwing their full determination into the creative process.

However, only one of them makes it to the finish line with a huge career advancement, while the other continues to flounder at the bottom of the profession.

Here's where the movie becomes subtly problematic: The dancer who fails does so in nearly every scene. She hurts her foot. She learns that she's overweight by dancer standards despite all appearances to the contrary. She copes with a hectic schedule. She just can't seem to get a break.

It's no surprise when the poor girl fails to impress the judges at a major event in New York City during the third act. As the story wraps up, she's still stuck in an endless stream of practice sessions while her successful colleague triumphantly pirouettes across a Manhattan rooftop.

Whether intentional or not, the juxtaposition comes across as mean-spirited and somewhat unfair. At a certain point, it might have made sense for Finzi to either drop her less capable subject or find a way to put the story in better context. As it stands, the movie simply condescends the dancer's (sizable) skill by directly comparing it to her colleague's superior abilities.

There's no indication that she shows any promise as a professional ballerina, even though -- to my layman eyes -- she seems pretty good at it. So the movie basically serves as a put-down for fifty percent of the time.

That said, the drama of the competition and the fluidity of the performances both make for a palpably moving experience. It's the underlying message embedded in the structure that could use some work.

In my initial reaction to the movie [2], I thought it might work well on a double bill with "Racing Dreams," another acclaimed documentary currently screening at Tribeca. The difference is that "Racing Dreams," Marshall Curry's portrait of adolescent Americans competing in the National Championship of the World Karting Association, contains a wide variety of characters.

The movie barely focuses on which ambitious 12-year-old can drive a car better than all the rest, instead emphasizing the way their various backgrounds fuel said ambition. Even the big winners endure bittersweet successes, as their futures behind the wheel remain unlikely. Mainly, "Racing Dreams" works because it has enough different personalities to keep anyone from competing for screen time.

Because of the dueling plots in "Dance," the contrast is sharp, unrelenting, brutal and utterly compassionless to the inferior contestant.

More than "Racing Dreams," the Tribeca documentary that has impressed me the most also testifies to the importance of understanding the manipulations techniques behind nonfiction filmmaking. Yoav Shamir's "Defamation," a darkly comic look at the Anti-Defamation League, contains a number of interviews with people both for and against the efforts of the organization.

Some claim that ADL head Abraham Foxman is living in the past, constantly reminding people of a genocide that's irrelevant to the plight of modern Jews. Others believe he's dead on. Shamir doesn't hide his own views, which lie somewhere between those two extremes, but he also doesn't force them on his audience. (The movie, by the way, landed a theatrical distribution deal with First Run Features last week.)

Shamir wisely reveals the construction of his film in several scenes. We witness the awkward moments at the beginning of the interview as his subjects get situated. This simultaneously illustrates certain character quirks while reminding us that these people didn't just drop into the movie out of left field.

In one striking moment, outspoken academic Norman Finkelstein -- reviled as a "self-hating Jew" and a "Holocaust denier" even though his parents survived Auschwitz -- jokingly salutes Hitler after his interview, and Shamir immediately explains on camera why the aside must belong in the film.

Many will argue with some of Shamir's points, but it's hard to strip him of that decision once you see it in context. Meanwhile, he displays a visible disdain for Foxman's grief-driven style without condescending to the Holocaust survivor's personal connection to his cause.

Godard once said that truth comes at 24 frames per second, and every cut is a lie. True, but at least Shamir lets us see the whole picture.