I would definitely err on the side of not recompositing anything, since as has been said, it guarantees the result to be the actual original without letting even any minute changes slip through. And as Baronlando points out, there are times when the effects actually don't seem to hold up with the digital re-composites, because they are too clean and too shiny to seem real, and their inherent imperfections become even easier to see. But then there are others where it is a definite improvement, so I'm pretty torn about it. And given the success achieved with adywan's ESB reconstruction and Harmy's despecialized versions, it seems generally worthwhile to be able to use them while just eliminating the actual changes. I read an interview with Gary Kurtz where he commented on being pleased with the digital compositing while deploring the CGI inserts at the same time, so clearly it's a hot topic among people who actually worked on the movies as well.