I think the only problems with the Lowry restoration is the fact that George asked for as little grain as possible to match them up with the digitally shot prequels, and that the Lowry team was given only a month per film. The official DVDs are free of dirt, obviously, but with more time to tweak and correct errors that their automated filters created (such as lost starfields, laser glow and non-white lightsaber cores) I think the Lowry team could have done a much more effective job in preserving more of the original look of the film.

Of course the color grading is a whole other matter...