Oh...Maul wasn't among the elite duelists of the SW mythos ? Nice to know that.
That depends on your standards for 'elite duelists'. Take into account that the three schmucks who went with Mace to fight Palpatine have been officially established as "some of the best bladesbeings the Order had ever produced". They are, then, among "the elite duelists". But among the very best? No.
And Bastila was a Padawan and, going by this, most likely not a master of a certain lightsaber style. They were both certainly skilled enough to give some of the most powerful beings in their respective times some trouble.
This is true, but nowhere does it say that those who use the double-bladed lightsaber equate to "leet duelists".
And there is also no reason to believe something different. Let's look at Mace "advantages".
No reason to believe something different? Hardly, Nai. The advantage of using a technique unfamiliar to one's opponent doesn't register to the undeniable proficiency Vaapad and Shatterpoint allows for. You've yet to prove otherwise.
Yes. The deadliest of the seven forms known to the PT era Jedi which wouldn't include Kun's style. Hence you can't draw the conclusion that Vaapad is superior to Kun's unique lightsaber style from that statement.
The deadliest of the seven forms taught in "the prime of the Jedi". Yes, I'd say that that - at the very least - puts it on equal footing with Kun's form.
They both were extremely skilled lightsaber wielders and they certainly both were deadly. Both of them were equipped with knowledge (if not mastery) of several lightsaber combat forms. So how do you want to determine who's lightsaber style (being the respective own invention of one of them) is the better ?
One is a form tailor-made for fighting Dark Jedi and Sith Lords, negating any potential combat advantages that they might possess coupled with a powerful ability to detect weaknesses and flaws in people and techniques and is near-impossible to master, thus making it rare. The other form? Is... ah... err... rare.
Hardly evens out, Nai.
Once more: Since when does "more powerful" mean "better combatant" ? That premise has already been proven wrong multiple times and the fight between Mace and Sidious would be one instance for that. Another example would be Mara Jade vs Jacen or Bane vs Kas'im. The most powerful force user isn't the 100 % winner.
If Mace's usage of Vaapad and detection of Shatterpoints is effective against Sidious - who is proven to be more powerful than Kun - then is it not both pitifully obvious and highly logical that it will also work on the weaker opponent? Kun isn't perfect. He isn't without flaws and thus his form is flawed as well. Meaning that it does indeed have weaknesses that Mace can exploit.
And aside of that: That "weakness" of Sidious if we go by the RotS novel was Anakin who was moving right into the room and it's even stated that Mace disarmed Sidious because the Sith Lord had to focus on the slippery ground (standing outside in the rain).
That detection allowed Mace to withstand and observe Palpatine's weakness during the Force battle. According to the novelization, Palpatine's fear made him hesitate and turn some of his Force-powered speed into a grip on the permacrete.
If you want to go by the movie I just see the superior swordsmen disarming the inferior.
How very flawed.
If we were to take that to heart, Nai, without delving deeper, you've just acknowledged that Anakin > Dooku since he pwned him and killed him [irregardless of the fact that it's already been proven].
And now ?
Except that that isn't the case. Mace is established to be an unnaturally offensive duelist, and Palpatine controlled the initial part of the fight, and butchered Kit Fisto while crossing blades with Mace. If we took the entire spectrum into consideration, Palpatine began the fight stronger than Mace [which makes sense, since Mace was unable to own him or beat him despite outnumbering him with "three of the Order's finest"]. Yet, as the novelization indicates, once he sinks into Vaapad, it negates Palpatine's advantage, and allows them to fight on even terms.
Neither Vaapad nor the Shatterpoint ability grant Mace the instant victory in a lightsaber fight. In fact we've seen the Shatterpoint ability failing and we also know that despite of using Vaapad Mace wasn't able to outduel Dooku when Dooku was a member of the Jedi Order, meaning that those style also doesn't mean guaranteed victory. As long as you don't want to say that creating a loop of Dark Side energy between the two combatants would lead to Kun's certain demise.
Dooku wasn't a Sith Lord at the time that he and Mace dueled, and as previously indicated, he didn't complete Vaapad at the time. The style works best against dark siders.