Matt Singer has an interesting piece at ScreenCrush about how ‘Han Shot First’ changed the course of Star Wars:
Whatever the motivation, the Han Solo [Lucas] conceived would not have shot Greedo first. The Han Solo that appeared in 1977’s Star Wars, however, did shoot Greedo before Greedo shot him, or at least that’s how it appeared to millions of viewers for 20 years (and in the original screenplay, as best I can tell). Both sides of this debate, then, have the same basic argument: Han Solo, a fictional character, wouldn’t do what he appears to do onscreen. They just disagree about which behavior is questionable.
That’s what makes “Han Shot First” one of the most fascinating pop cultural phenomenons of the late 20th and early 21st centuries. It seemed to become the test case for many subsequent battles over who should control a work of art — its creator or its audience. It’s ultimately not even about Han Solo. It’s about authorship.
Changing the film to have Greedo shoot first certainly undoes a lot of the characterization of Han that Lucas himself ostensibly established: that he was a carefree rogue who only gave a crap about himself, before discovering love and loyalty during the events of A New Hope. It’s a great arc and having Han simply reacting to Greedo somewhat undercuts it.
But beyond that, my problems with Greedo shooting first are far more basic. Like many of the other changes in the Star Wars Special Editions, it just looks awful. Just look at the original Special Edition:
It is totally unconvincing and has not aged well. The visual effects for this scene were made somewhat more palatable for the Blu-Ray by shortening the length of time between shots, but not really.