bobgarcia74:
Well, Bob - I think this is probably the next best option. However... it still doesn't explain why Anakin seems troubled over his actions. If he's cocky and gloating when he kills Dooku - which you nail perfectly in your clip - it's a little strange that 1 second later, he looks like he regrets it. It's okay for him to regret it later, but he should at least have a little transition time. The suddenly-feeling-remorse-in-the-next-shot feels too awkward. The sudden remorse only works in the original context, and in a heat-of-the-moment context, I think.

If there was somehow a way to get a transition period like... "My powers have doubled since the last time we met, Count," then he kills Dooku. As Dooku crumples to the floor, Anakin lets out a spiteful, nonvocal laugh and gives a "See how awesome I am?" look to Palpatine before realizing what he just did, and feeling some remorse.

But other than that... it would seem strange. Unless there's a better way to make Anakin kill Dooku in the heat of the moment.

silverkey:
That youtube clip there is bobgarcia's.

Yeah, I think these scenes are supposed to mirror eachother. But thematically/dramatically speaking... I don't think they HAVE to. Especially since - at that point later in the film - Anakin shouldn't still be protesting about "the Jedi way" when he's just moments from selling his soul to Palpatine. It works in the original cut because most of Anakin's motivations simply come from the fact that he's being pressured. He's like a cornered mouse, and it makes him weak. In my edit, Anakin is never pressured into doing things. He either does things off-the-cuff, or entirely willfully. His killing of Mace will be a well-considered action. Think Darth Vader saving Luke in RotJ. I'm going for a more powerful mirror-scene between RotS and RotJ.