Vader may have grown in power, mastery, knowledge and technique. But I have always had the opinion that Vader before Mustafar was the closest he ever got to Sidious. His fighting style, the wild overwhelming juggernaut that he'd become by that point was just unmatched. That Chosen One potential was really starting to pick up the slack in terms of his augmentation and focus.
The Vader style of fighting that stomped Dooku and Drallig is just more effective in combat, gotta go with him.
Originally posted by SunRazer
Somebody did raise an argument about how Cin was also fighting clones at the time. Can't remember what that argument was, or who raised it (I think it was Sas, though).
Yeah, it was me.
Stone-faced, Obi-Wan watched younglings run into the room, fleeing a storm of blasterfire; he watched Cin Drallig and a pair of teenage Padawans-was that Whie, the boy Yoda had brought to Vjun?-backing into the scene, blades whirling, cutting down the advancing clone troopers with deflected bolts.He watched a lightsaber blade flick into the shot, cutting down first one Padawan, then the other. He watched the brisk stride of a caped figure who hacked through Drallig's shoulder, then stood aside as the old Troll fell dying to let the rest of the clones blast the children to shreds.
Src: ROTS