I think Lucas, and he has stated this in interviews, felt freed up by CG in ways that the more photochemical optical fx could never deliver. But it comes back to the old saying that jst because you can do something doesn't mean you should. I just think he overreached. CG is certainly a terrific new tool for the tool box but it has to be used for things that can really only be done no other way. That is paraphrasing the fx legend Dennis Muren. Even John Knoll when he was making Pirates 2 mentioned how he was excited to be working on sets with live action actors and then using their on-set motion capture system(imocap) rather than having to do the mocap seperately in a studio divorced from the interaction with the other actors. ILM has worked hard over the last half decade since ROTS to bring CG camera setups and data capture into more workable setups for live action shooting while making their "footprint" on-set less intrusive. I hope they really stretch that in the ST with massive on-set mo cap capture. Then you're actually working with actors with actors, regardless if an actor is going to be replaced later with a CG creature. The Phantom Menace started that whole process with Ahmed Best as Jar Jar, but well.....an annoying character is annoying no matter how he is realized. Ahmed playing Jar Jar would have been every bit as annoying.