Alright I just finished, I was lucky enough to catch it when someone accidentally unlocked it.
As far as characters go:
-Same voice actor but they are going to approach Noctis' voice direction differently.
-Prompto will need to"step it up".
-They will not change Cindy's design, but will try to present her in a less sexual manner.
As far as combat goes:
-A lot of features have already been added since the demo's release and were left out of the demo's release
-Difficulty modes.
-Remappable controls (possibly).
Overall:
-I think they are approaching the feedback in a pretty level-headed way and I don't think anybody should be worried about "Feedback Fantasy".
-Episode Duscae might be periodically patched and treated like a sort of beta. (edit: they aren't sure about this yet, but they say that they would like to.)
-Those who bought the digital version of Type-0 will be able to provide feedback in the surveys with a new different system.