In a way saving the prequels and Jedi (for those who feel they require salvation) is a more rewarding challenge.

ANH and ESB are so highly regarded that almost any proposed change will be met with heresy accusations by the faithful (just rewind to the blue/grey TIE Fighter debate).

The PT (and Jedi to a lesser extent) offer more options for change without stamping on sacred ground.

The flip side being that to bring them up in quality significantly requires more imagination and a lot more work.

I think the important thing to remember in this kind of project (and please correct me if I'm out of line here) is to figure out what the story is that was attempted to be told and rework each film so they tell those stories in a way consistent with what went before.

For example ANH and ESB have humour but it's a bit more sophisticated than the childish slapstick and toilet humour we saw in the PT and ROTJ.

TPM had a very similar story to tell as ANH but where ANH takes us through that story in a linear fashion TPM darts all over the place.

A reworking of the PT and Jedi doesn't have to be a gutting exercise (apparently early edits of ANH were just as problematic as the PT).

Shifting elements around and replacing what is beyond repair can tell the same stories but in a way that sits better (not that I'm against projects which tell very different stories too but these projects don't seem to be in that vein).

I shall stop now as this is the ESB:R thread but I'm looking forward (a long way off) to seeing what Ady and others do with PT perhaps even more than I'm looking forward to this project (and this one is going to be like several childhood Christmases arriving at once).