The weird thing in those 2004 DVD commentaries is that it has no mentions to the new stuff and changes that have been done for this edition. It seems that they have recorded the commentaries BEFORE doing the DVD changes. I think it was too bad, just cause I was waiting for some explanations about that.
The only mention is from Ben Burtt, concerning the Naboo shot in the ROTJ celebration, but it's all...

Concerning the commentaries themselves, I must say that I love ESB one, especially for Kershner. He's very interesting, verry funny, and give us some good anecdotes on the filming of the movie.
Lucas talk only about the story, but it's really interesting too.

So, just for the commentaries, you MUST borrow them to a friend. The best "special feature" for the OT at this time, IMO.