We watched Ratatouille tonight. One of the user comments on that imdb page says it's a "feel-good movie," which it is, but it's not as saccharine as those movies can be. It was a fine movie to watch but it's so much less of a Pixar movie than a Disney one. Pixar movies have a lot of depth: there are sad times and quiet times which balance the unrelenting ups, and the characters themselves are quite deep. In this movie, the sad times were less sad and more predictable and the characters are superficial - more like a standard Disney movie.
As well, Pixar movies usually create their own world where the movie exists and everything within that world is consistent and believable. But because Ratatouille is set in our world, it wasn't as believable. Overall, Ratatouille is a fun and enjoyable movie but not as good as, say, Wall-E or Cars or Monsters, Inc.
There's a short on the DVD off of the main menu describing the history of the rat and it's well-worth watching called Your Friend the Rat. It's description of Alberta's rat-free status (and how that came to be) is hilarious. Definitely watch this one. :)