Along with doubleofive's extensive and definitive 'A New Hope Revisited Changes List': http://doubleofive.wordpress.com/anhr-change-list/ , his 'Visual Comparison' screenshots make for a very interesting compilation of Adywan's many excellent improvements.
I hope he'll end up doing similarly comprehensive comparisons of Adywan's future edits too, eventually.... :)
I only bring this up because I've just come across and re-read the following 'changes' articles that were written 5 years ago when the 2004 Special Edition DVDs of the OT were originally released....which gave me the best comparison by far at the time of what had been altered, but which also made me tear my hair out due to some of the 'creative choices' they showed....
Now that I've finally got the kind of 'Special Edition' of 'SW:ANH' that I longed for at the time (thanks to 'Revisited'), it was quite fascinating to go through these articles again, to see the points and remarks that were made at the time.... They include a lot of comparison screenshots from the Original Theatrical/SE theatrical/SE DVDs, and being reminded of some of the quality issues on the DVDs made me nervous about what the Blu-ray versions will end up like for the masses....
SW:ANH 'changes' - http://www.dvdactive.com/editorial/articles/star-wars-the-changes-part-one.html
SW:ESB 'changes' - http://www.dvdactive.com/editorial/articles/star-wars-the-changes-part-two.html
SW:ROTJ 'changes' - http://www.dvdactive.com/editorial/articles/star-wars-the-changes-part-three.html
(and for the sake of completion, the one done later which discussed the Prequel 'changes') - http://www.dvdactive.com/editorial/articles/star-wars-the-changes-part-four.html
Oh, and keep scrolling down at the end of each article to see some interesting comments at the time, which had additional info. in them.