it's funny, but with the exception of inserting Jabba into A New Hope, all the major changes that the fans hated had nothing to do with the limitations of technology at the time. Greedo shooting first, dialogue switches, Jedi Rocks!,Boba Fett picking up chicks in Jabbas palace, Audrey 2 in the sarlaac pit, the ewok celebration, the recycled footage from Jedi of Vader returning in his shuttle from bespin, were all cases of Lucas simply changing his mind.

To be honest I can quite happily live with the changes that were made to genuinely improve previous effects shots, like the dewbacks,the windows in cloud city, the tentacles in the sarlaac, space battles etc.