Out of all the animals in the wild, it's especially fun to watch chimps because they're so easy to project our human emotions on. DisneyNature documentaries do what Disney does best by creating emotionally rousing stories out of beautifully captured footage, showing us the (manufactured?) drama and sweetness of the animal world. Unlike African Cats, this one is much more suitable for younger audiences--in fact, I would say that unless you're a Jane Goodall groupie and/or love chimpanzees, it's more satisfying for younger viewers than people who want to get their hearts pumping.
Oscar is at the center of this story, and the audience is allowed to get intimately familiar with how annoying he is to his troop (strangely coincidental to Oskar in Extremely Loud and Incredibly Close). There are countless, gorgeous shots of the African jungle with these precious guys just doing what they do--eating, swinging, playing, grooming, and lounging. Tim Allen narrates the story with a good balance of jokes and seriousness (and his trademark grunting). A big part of this story is how, developmentally, chimps are highly reliant on their mothers for everything. While the older chimps are able to use tools and find food, the babies are pretty much helpless (which makes Oscar seem even more irritating than he probably is to his mama chimp). It's easy to fall in love with the little guy.
Oscar's troop is like the 1%, made up of a smaller number of older chimps who have all the food. So, the 99% troop nearby, who are all cranky, poorly organized and hungry, want to take over the better territory. I might have unrealistic expectations for a nature documentary, but I never quite bought this as a real danger. Even during the climax of the film, I wasn't terribly disturbed. I remember feeling like March of the Penguins was on par with Sophie's Choice. Now that was brutal.
Anyway, in typical Disney fashion, there needs to be a heartwarming ending. Audiences see an unprecedented move in the chimpanzee community that is both dramatic and sweet, just like we're expecting. But during the credits, where they show what the camera crew went through to get these shots under such extreme circumstances, I had the familiar feeling of wanting to see that documentary instead. Since your kids won't be plagued by the same feeling, I'm sure they'll be appropriately enamored with it, and ask you for a chimp for their birthday. Just get one old enough to use tools so he can help you crack nuts.