I’m a younger SW fan, so I grew up with the 2004 editions on DVD. For me it’s the little things, like the audio for “the first transport is away” is redone and it makes the moment that bit nicer. There are other very minor audio changes - and colour changes - that just enhance the film for me, and I like the different variations on the Imperial march. It might be an iconic track but hearing the same excerpt over and over every time a star destroyer is onscreen starts to become grating.
There are the usual dumb changes, particularly dialogue changes, but I agree I generally like the special edition more. It’s probably the best of the OT special editions