I have the Emperor`s New Groove CE. Picture is very good but very difficult to compare a traditional animated movie against a computer generated one. However Emperor has great picture and sound. If you are interested in the whole process of making the movie then get the CE. If you only want the movie then the standard release is okay.
The Target near where I live has both versions the same price! The second disc has some nice features, but nothing earth-shattering. I think if I had to choose between paying $30 for the CE and $20 for the regular, I'd probably go for the standard version and save the $10.