i don't think that this kind of comparison is accurate. Luke, Vader and all the force users of the "new republic" are like padawans compared with those of the old one. Only Dooku and Sidious represent the "old school". Thus, according to the kotor storyline (which is the only source we have about the force users of the old republic) the most powerful force user is Revan (aka the TRUE LORD of the Sith).
I quote:"Revan was Power - it was like staring into the Heart of the Force. Even then, I could see the Jedi he'd slay etched on his soul"
