Saber wise, his mastery of Makashi plus other forms > Maul's Juyo mastery.
Now granted that Juyo is a very aggressive form (which excels against Makashi), the fact that it is an incomplete form + the fact that Dooku has mastered other forms + the fact that Dooku utilises Makashi in an unorthodox manner + the fact that Dooku is damn skilled and has way more experience with his form leads me to believe that Maul still has no chance.
Force wise, Dooku has displayed far more power (shown in his force fight with Yoda, Maul has shown what exactly?), better control (lifting both Anakin and Kenobi up at the same time) and has way more knowledge; years and years of experience with both the light and dark side of the force, he also knows force lightning among other things. He is also in the know and possession of many sith secrets, such as Darth Andeddu's holocron.
Testament to his skill is how in Dark Rendezvous, Assaj Ventress says something which displeases the count and he instantly brings her to her knees with some next force attack, and she couldn't do jack to defend against it.
Another great thing about Dooku is how he duels, with just one hand. Now this coupled along with the fact that he is an incredibly gifted and experienced duelist means that he finds it especially easy to pull off a force attack while in a duel. Now obviously against someone like Yoda he wouldn't be able to pull it off, but Darth Maul is no Yoda.
So because I have a Maul sig and avator you just assume I'm a Maul fanboy? You don't just assume that I like Maul but am not a fanboy of him? You have got to be Black Fox if you know about me and Rampant Ox, too.