Forget Monsters vs. Aliens! I'm saving my money to see "Man vs. Cheetah!"
I haven't seen the movie in question, but I would suggest that you skip it or wait until it comes out on DVD. Like you, I'm a Pixar snob. All of the other cartoons seem to rely too much on potty/gross-out humor, and I doubt this one would be an exception. Besides, I don't think the current 3D technology is that great. It just gives me a headache. So save your $8.50 and rent it for $0.99 in a few months.