Dooku is a mystery. I'm not sure if he ever wanted to kill Obi Wan, Yoda or Anakin in his respective confrontations with them. It's very interesting the way Lucas got Lee to play it: When Dooku is blasting Yoda with his lightning in Episode II, he's only using one hand. His face also seems somewhat exasperated and fretful. This is all in marked contrast to the way Sidious fights Yoda in Episode III. Dooku clearly prefers brandishing a lightsabre; his facial expression as he's delivering the line about "skills with a lightsabre" is a clear indication of this - as is his curved handle and very elegant, highly developed swinging style. Ultimately, I think Dooku was less powerful than Sidious. He always seemed to be holding back one way or the other. He wasn't the conduit for the Dark Side that Sidious was. He didn't even have reptilian eyes! I see Dooku as a man caught hopelessly between two worlds. He was following his own code - but that code had snippets of his old life as a Jedi and snippets of his new life as a Sith mixed together. I think Dooku knew he was in a slippery position and planned to get out of it; he never did, of course. No man can ever stand up straight or run properly when walking on ice.