Do you think that a good side ghost of him is the redemption?

I don't think that is the redeeming moment... It is when he says "tell your sister you were right about me."

And saving Luke

The ghost is like I said wrapping the neat bow around it all... If anything it's over sentimental but I think messing around with it has made it a lot worse.

The Ghost...It's like a window to what Vader would have been if he were not Darth Vader Tortured soul that he was. But we already saw him come out of the evil trance like state he was in under the control of the emperor. He was neither a Jedi or a particularly good person but he did the right thing in the end for the love of his family.