Originally posted by TheIndyJedi
Vader obviously isn't better than Emperor or peak Revenge of the Sith Anakin but he is still better than Maul and Dooku even if he is on their tier.
And it is more evident in canon.
I think when the quote says he is like Maul or Dooku, he is basically saying that like them he is an apprentice of Sidious whose powers never grew to be on par with Sidious.
Doesnt mean his powers can not be above Mauls or Dookus at their peak.