I saw it on Friday, I would wait till it came out on DVD.
As far as Disney Films go, using Toy Story and Lion King Ect. as the A movies I would give this one a C-. Nowhere near as good as Cars or the Incredibles. They humor seemed forced and the story left too many open ends. My boys, 7 and 5 didn't say much about it the rest of the day like they did with the other films.