Bring_My_Shuttle said:
...
The devil's in the details. For example, there was a poetry with Luke cutting off Vader's hand in ROTJ, seeing it was mechanical, and it dawning on him that he was in danger of turning into the same as he contemplated his own mechanical hand. In the PT, Vader got his hand and legs cut off, and left to burn and die a painful slow death by Kenobi. It just crapped on that ROTJ moment, and showed Kenobi to be a sadistic hat to boot.
...
I would add to this that while Anakin still needed to have fallen into the volcano (that's right..VOLCANO, not some lava river), Ben needn't have cut his arms and legs off. They could have lost in the volcano.
Mostly, I would have liked to see Ben think Anakin has died, only to discover later the new leader of the Imperial forces, Darth Vader, was actually Anakin. When Ben was talking to Luke, he knew Darth Vader was a pupil of his who turned to the dark side of the force. In Episode III, the connection that Ben knows about Vader isn't really there.