The reason that they did what they did with Jabba in episode IV is explained in the special features. originally the scene was shot with Harrison Ford talking to a portly fellow who was a human actor. He was replaced by the CG Jabba, but the Jabba of Return of the Jedi was far too large to fit in that space. Han Solo encircles the human character as they speak and so he would have gone right through the larger Jabba character. Their solution: make a cgi monster that looks kind of like Jabba but smaller, and put the scene in the trilogy, instead of leaving it out as it clearly wasn't needed. I actually have no gripes with the rest of the upgrades to A New Hope, except of course Greedo Shoots First. Which is ridiculous. I made sure to buy the two-disc collector's edition DVD that has the original print of the film on it, so I can see it the way it was supposed to be. However that disc is a non-anamorphic transfer that didn't get the love it deserved. Lucas is ignorant of the cultural phenomenon he created. He obviously fails to understand what made it great and why people loved it. Empire has no really noticeable upgrades because honestly it didn't need any. The original cut of the film is a remarkable improvement from A New Hope, and for something made in 1980 looks and sounds phenomenal. As such, it's the least hurt by the changes. Nevertheless, in the most recent version the scene where Darth Vader speaks to the Emperor on the holodeck is changed. The original actor was replaced with Ian McDiarmid - the Emperor of the rest of the series. Some lines are changed, but worse, that actor is now removed from the trilogy. Sad :( Honestly I haven't even watched Jedi recently enough to be appalled at the changes. I only really remember the 1997 special edition cause it's the one I've seen the most. But I do have the original cut and will watch it soon.