Just relax and enjoy the fact that there's a servicable animated version of Willy Wonka. It is quite fun to watch and 75% of the voice actors did a phenomal job. Sure, the animation is pretty weak and there are some cheesy moments.. but it doesn't take away from the overall charm of the movie.
My daughter is a huge Gene Wilder Willy Wonka fan, and she absolutely loves this adaptation. It's worth getting for the kids... and I'm sure you will have fun watching it with them. It would also be a great way to introduce the story to young ones who haven't seen any of the live action films.