Originally posted by DARTH POWERMace Windu and Dooku certainly were, and this was demonstrated (Yoda: Dark Rendezvous; Shatterpoint): refer to the Darth Tyranus Vs Revan | Vader Vs Malgus + Revan, HoT, Malgus Vs Caedus, Krayt, Anakin threads for a more in depth and complete explanation to why Windu and Dooku were right there with Vader in the 80% of Sidious pool.
and he is the one who said Vader is 80% as powerful as Sidious. I doubt Dooku or Windu are more powerful than that.
Yes, I believe they'd cream Vader far more expediently than RoTJ Luke, and regret voting for Vader out of a momentary brainlock.
Starkiller II's form was designed by Vader to allow him to fall into an unbeatable defense - Starkiller II's style =/= Windu and Dooku's superior styles to all, perhaps even Tulak Hord and NJO Luke, or at least rivaling the greatest styles.