The Vader power thing is a source of constant debate among nerds
Anakin Skywalker was peerless in his power, even ignoring the whole stupid Midiclorians thing that was designed frankly to quantify how powerful someone is.
Among the powers that he had he also had prophesy which was a major part of his downfall.]
In the Revenge of the Sith book after his transformation he was described as a artist who had lost his ability to be a great artist, the power was there but beyond his reach. In the book dark lord which was sadly made legends, but was the best Vader book out there, he talked about his ability to peer through the force at future events as being burned out, his ability to do things like force jumps and the such severely hampered.
The things that made Palpatine happy were really three fold.
That Vader killed his wife, he just at that point realized that Palpatine was the only one who would ever accept him for the monster that he had become, a traitor, a murderer a man who killed the thing most dear to him. For their relationship based around eventual betrayal, Palpatine was the closest thing to a friend and a mentor that Anakan/Vader had
That Vader had been brutally injured and needed the suit to live. In Dark Lord they had a great conversation where Palpatine basically asked Vader why he wouldn't betray him and Palpatine made sure that Vader knew that he was completely vulnerable in that walking iron lung and . . . .
That Palpatine had lied so effectively that Vader believed that Palpatine was his path to greater knowledge and power.
If Anakin hadn't been injured, I doubt that Palpatine would have lived long and as powerful as Palpatine was, Anakin was probably more purely powerful though he certainly didn't have Palpatine's other gifts.
But Palpatine knew that Vader was psychologically and physically damaged to the point that while he was still powerful and frightening to nornal people, he was nothing more then a slave to Palpatine, which was ironic because Palpatines seduction of Vader was based around enough power to be free of constraints.