Anakin was faster, more skilled and more agile than Vader, on top of being as strong as him.
Not trying to lowball Vader, but he has been tagged in lightsaber duels by people slower and less skilled than Dooku.
What dueling feats does Vader have that can show he would beat an ROTS Anakin/Dooku? Or are we just going to use the overplayed "Dooku is weak against strength" (Which really isn't even true)
While it is ABC logic and should be taken with a grain of salt, do note that in the ROTJ Luke vs ROTS Anakin sabers only thread, Ani won, and in the Dooku vs ROTJ Luke sabers only thread, Dooku won.
Just something to think about.
Well ROTJ Luke simply has not come into his own yet. DE Luke, on the other hand... Also note ROTJ Luke is either a piker or entirely the result of power scaling vs. Vader.
And ROTJ Vader beats ROTS Anakin in every thread they go head to head in. What he lost in potential, he gained in skill and actually working hard to overcome his new handicaps.