Some of these things are hard to call enhancements when they are probably rushed unfinshed works or oversighted errors in color, sound and FX.
I'm still at a loss for how these discs were released without someone spotting and correcting alot of obvious errors, despite a looming release date, more care should have taken to allow an appropriate amount of time needed instead of a "it's good enough" or I could give a rats ass approach, considering the OT needed to be remastered and effects touched up, it's inexcusable that the release wasn't better planned for by Lucas.
My guess is most of the errors have been noted and they will be corrected when the 6 movies are released, if not someone needs to be shot.