I think the one SE change that I can honestly say is really excellent is the re-introduction of the scene with Biggs and Red Leader in ANH. It would be great to see the earlier scenes on Tatooine put back in as well. It makes the previously background-less comment by Luke ("Biggs is right, I'm never going to get out of here") pay off by connecting more sturdily with the character we previously only met once the BY was under way.

Cleaning up blue screen effects shots (e.g. on Hoth), altering the perspective of the cell block corridor, etc. I don't have a big problem with. I liked the introduction of windows in the corridors of Cloud City.

I still haven't watched the 2004 SEs, just the 1997 versions. The one thing I thought would have been done in 1997 and wasn't was putting Ian McDiarmid in ESB. I think it provides some nice continuity between ESB and ROTJ. But I fail to see why the script needed to be altered.

I regard all the other changes as surplus to requirements.