...Ummm they changed the Emperor's head for a pretty good reason considering the fact that Ian McDiarmid had played Palpatine in every film EXCEPT ESB. It was purely for continuity reasons. And it works, IMO. As for the dialogue, it didn't change anything. It just heightens the fact that Vader is trying to get Luke to turn without the Emperor knowing of it.
So what do you guys do with your Comicbooks, tradingcards, records, CDs, DVDs, photo albums, home videos, artwork, and tapings of your favorite shows? 99% of those things arnt going to change or start getting any newer, why do you keep them around? Surely they suck now by the current "logic" provided here.