Mace was actually moving pretty slow, Agen and Saesee displayed worse reflexes than Mace or Kit did, Kit moves quickly, the quickest of all four jedi in my eyes, just look at how he pulls of this real quick spin.
Finally someone who agrees with me!!!
What has Kit done? Won a battle at Mon Calamari due to the fact that the battle took palce underwater, got defeated by Asajj in a close one in The Cestus Deception and got pwnd by Sidious in 7 seconds even though he was fighting besides perhaps the best Jedi dueler in the order.
Prior to their duel, Asajj unleashed a barrage of mercenaries on Kit (and Obi-Wan) in order to STUDY how he fought, and hence work out his weakness. Not only was she able to gain much advantage by just watching how Kit fought, but her mercenaries would have likely tired Kit out, thus creating more of an advantage for the dark Jedi.
If you’ve read the Cestus Deception, you would also know that apparently, Asajj came within a hairbreadth of defeating Mace Windu.
Qui-Gon would have beaten TCD Asajj, even Obsession Asajj he'd give a run for her money, and he's have lasted at least twice as long as Kit did against Sidious.
And how do you know this?
Qui-Gon lacks speed and dexterity because of his old age. In the Phantom Menace novel, it also mentions Qui-Gon’s strength diminishing because of his old age.
I also believe that Shaak Ti once stated that Kit Fisto, Mace Windu, Agen Kolar, and Saesee Tiin were the BEST Jedi in the order (probably with the inclusion of Yoda). Qui-Gon Jiin may have been very powerful in his prime, but I doubt he would have been able to last any longer than the other Jedi in the room against Sidious during the time of TPM.