The difference in power between then is quite significant. Aside from a few novelized comments Dooku made pertaining to Palpatine being > he, and the fact that it's been stated numerous times that Palps is the most powerful Sith lord ever, the difference between them can be clearly seen on screen.
For instance, AotC Obi-Wan was able to casually block Dooku's force lightning as though it were no more significant then a blaster bolt. Other side of the coin, it took nearly everything RotS Mace had (while immersed in Vaapad), just to redirect Palpatine's lightning. That alone denotes a huge difference in force powa. There's also their respective battles with Yoda. When Dooku battled Yoda, it was clear Yoda was the definitive superior in both the force and lightsaber battles. Dooku made Yoda work a bit during the saber portion, but Yoda was still clearly superior. Other side of the coin, while Palpatine and Yoda appeared to be fairly equal during their saber battle, Palpatine seemed to have the edge during the force fight. So yeah...
As far as technical skill with a blade goes, I'm not quite sure who's better. I know for certain that Palps would crush Dooku in a duel, but that's mostly because of Palpatine's force-amped abilities (speed mainly) with which he could use to essentially blitz Dooku.
"I am tired of Earth. These people.
I am tired of being caught in the tangle of their lives."
^ The situations Galan provided aren't especially accurate; Windu was physically closer to Palpatine than Kenobi was to Dooku and the Count was only using a single gout of lightning as opposed to Palpatine's two.
That said, Dark Rendezvous, Labyrinth of Evil, and the Revenge of the Sith's novelization all depict scenes in which the Count regards Palpatine with an overwhelming mixture of fear and awe, despite the fact that he was the public leader of galaxy-spanning faction equipped with quadrillions of battle droids and the beneficiary of overwhelming wealth, to say nothing of the Count's own prodigious skill and power.
Suffice it to say that Dooku, the man who casually threw himself against Yoda, would have very little reason to fear anyone, and yet still found that he would "not question the power of Darth Sidious. The dark secrets at his command."