Buy it. If you watched the trailer with glee then you will like this movie and can watch it in theaters. If you find yourself subscribing to more and more stories that follow the tropes of typical Asian and American Anime's, then this movie is for you. If not, then definitely wait to Red box this one.
Brief Overview (No Spoilers)
The main character is a kid named Kudo who loves to tell stories and the movie progresses by mixing the reality that Kudo lives in with the stories that he tells. This mixture combined with the stylistic animation make for an enjoyable and peaceful kind of movie going experience.
This movie is a delight to watch with a compelling story and art style that either will sell you more into the experience or break you away from it. While other critics have aired their complaints about the stories weak points, I argue that the overall story based on the merits of its genre make it a good standalone film that can match up against Pixar's great stories.
What I mean by it's genre is that this movie is more of an Anime style story. That being said, the expectation of the story and the style in which it is delivered then shifts. With a Pixar film, the expectation is for a Western style story that can be universally felt for audiences everywhere. Anime is more a niche market as far as audiences go.
Other film critics have put in more eloquent words what the plot has and lacks. The biggest concern for the majority is the rather lack luster ending which seems to go into a cliched "Happy Ending".
These points are valid but are said with the expectations of a Western Style Story. If seen through the lens of an Anime style story, this movie is a home run hit and stays within the realms of its storytelling rules while at the same time being a very meta kind of story that pushes certain Anime rules. This is seen in the first 15 min. where Kudo repeats the phrase: "If you must blink, do it now..." This is a true mark of the relationship that Kudo's stories have with his own story and is a very important point about the kind of story you are about to watch as a movie goer. It is through this understanding of the kind of story you are about to watch that will correctly set your expectation and enjoyment of the movie. Apart from genre and story telling styles the voice acting was also well done.
Mcconaughey was especially well acted where you couldn't tell too much that it was actually him voicing the Beatle/Kudo's dad. Charlize Theron was very much herself and if you like her, you will like her characters as well.