I dunno, usually when you get CGI blended with regular 2D animation, it stands out like a sore thumb and takes away from the experience for me. I role my eyes every time they unnecessarily use it in Avatar, for example, and I hate how half the attacks in the Pokemon anime are CGI now. Futurama does a fairly good job of it, except whenever one of the characters who are regularly 2D get rendered in 3D, then it looks weird - but the ships and whatnot are always CGI, so you get used to the natural divide. Sometimes it can even be pulled off in such a way that you can't really tell the difference, like in Princess Mononoke, but usually that's not the case.