Ryan McAvoy said:

If it's also true (As is often said) that Marquand didn't have the same clout as Kirsch to rewrite/change things, then ROTJ must be almost undilluted from script to screen and therefore the best!

Actually if you read "Making of Jedi" carefully you should've noticed some pics of the ROTJ script that clearly show some changes made by Marquand by hand (the dialogue between Luke and Leia). Also Rinzler wrote that Marquand handed over Leia's speech to Mon Mothma in the briefing scene.