The scene in the original cut of ESB where Mr Vader has a chat with Mr Palpatine - did Lucas change the performance to one from Ian McDiarmid for the current incarnation of his "artistic" "vision"?
This is one change that I actually would have welcomed in the 1997 SE.
Personally, I feel that ESB survived the best in 1997, with largely cosmetic changes made. The one thing that grated was an apparently insignificant change - Mr Vader, in the original cut, just after Luke has thrown himself into the void rather than join him, is walking through a corridor in Cloud City and James Earl Jones growls: "Bring my shuttle" - expressing very well Mr Vader's emotional state at that point in proceedings.
In the SE release of 1997 the line was changed, although the same shot was still in place. The rather flabbier and less expressive phrase: "Alert my Star Destroyer to prepare for my arrival" (or something equally as crap) is used. Where, before, we had a terse, explosive line, which JEJ uses to full potential, we instead have to suffer through a line which is twice as long and says exactly the same thing but with less expression of Mr Vader's feelings.
This one change annoys me like no other, because, as I say, ESB otherwise was relatively unchanged.
Quite how this gets ESB anywhere closer to the fabled "artistic" "vision" I have no idea...
I should point out that I have not purchased any DVDs of any version of any of episodes 1-6 as yet, so I have not taken into account any further revisions subsequent to the 1997 release.