I really don't like to agree with the theory that the cyborg-enhanced Darth Vader was a poor Force user. It just doesn't make any sense to me. First, it confirms the joke that people have been passing around that since the Force is now explained to be a scientific lifeform tied to one's cells, that if one had less body, they have less Force. And that's just stupid. Plus, the first time I heard it was when George was trying to dance around why the lightsaber fight in the first movie was not as intense as those in the other movies. "One's an old man, and the other's mostly machine, not man." Well, then why was he able to kick so much ass in the sequels?

And most importantly, why would the Emperor go to the trouble of keeping him if he now sucked? He never seemed to give a crap about his other apprentices. He told General *groan* Grievous that his new apprentice (Anakin) would be younger and stronger. Well, if his accident caused him to lose that much power (which I really doubt it did), why would Palpatine travel all the way to Mustafar and rebuild him and then keep him around for a generation? I'm sure he could have found someone else he could have trained in the Sith Arts if Darth Vader was now that bad.

But that's simply because he's not so bad. The Force is a spiritual thing, and no amount of lost limbs should detract from using that ability.