I say the Sith win round one. Sidious is the undisputed master of Force attacks, Bane "nudged" a moon and toppled a building with a wave of pure energy, and Exar... Need I elaborate?
I say the Jedi win round two. Their numbers include five of the greatest swordsmen in SW history. The Sith are incredible duelists, but the 5 to 3 odds make things difficult for them. In the end, numbers win this battle.
I say the Sith win round three. In an overall battle, DE Sidious could probably take Mace and Yoda, or at least hold them off until more help arrives. I'd be willing to bargain that Bane and Exar could take on Anakin, Obi-wan, and Qui-gon. I say one dies, but the other attains victory and could then help Sidious crush Mace and Yoda. Another one dies in that battle, but one Sith remains standing, while no Jedi do.
I'm going to play the devil's advocate here. The Jedi, I believe, win round two. Qui-gon Jinn was stated to be a lightsaber prodigy. Obi-wan, by RotS, beat Anakin and Grievous, the latter of which being able to strike sixteen times per second. Anakin beat Dooku, who was one of the greatest duelists of all time. Yoda and Mace are self explanatory.
If Anakin was in the same state of mind as when he fought Dooku then the Jedi might have a chance. Qui-Gon (as awesome as he is) was never really an exceptional duellist. He was better than most but still a firm notch or two behind the Orders best. He got beaten by Maul (a weak fighter in comparison to others) even after he had meditated and become fully revitalised. I also dont think numbers will play a very big part. We have seen Sith fight multiple opponents before and emerge victorious.
Darth Bane's easily the strongest here, he's insanely quick, and on par with Kas'im, the guy who mastered all 7 lightsaber forms, and then spent decades perfecting each form, and refining his skills.
Darth Sidious in RotS was basically superior to all of the jedi listed except Yoda, who he was close to, and this was when he was 13 years our of practise, and old. By DE, he's much stronger in the force, his clone body is in peak physical condition, and he's insanely quick.
Exar Kun was slightly better than Ulic Quel-Droma, someone who was able to stalemate Sylvar, an extremely powerful jedi who was tapping into the darkside.
All three are firmly better than Yoda, and leagues above the others.
While yoda and sidious fight, qui-gon and obi-wan naturally join to fight ok, let's say, bane, while windu and anakin fight exar kun. After a while, while sidious is still fighting yoda, bane kills qui-gon and obi-wan. When he does this, windu and anakin kill exar kun (don't come with bullshit, windu+vaapad and anakin+anger can own even sidious). After this windu decides to help yoda who is losing, leting bane fighting anakin. While windu and yoda kill sidious, bane gives a force storm on anakin and let him out of the fight. Then windu and yoda finish him off...
Yes. She was able to defeat three strong Massasi warriors with her bare hands in seconds, she was able to sneak up on Oss Wilum, an exceptional jedi, and knock him to the ground with the hilt of the saber. It's also constantly implied throughout the comics that she's one of the top jedi, and she's pretty badass in action.
The Sith will win in everything but Saber combat. In a saber battle the Sith get owned.
In a Force battle though the Sith win rather handily. In an All out battle I'd say that the Sith still win, but Palpatine might end up killing everyone but himself.
The two lesser Sith engage the Jedi long enough for Palpatine to get decently far away in order to kill everyone (Bane and Kun included) with a Force Storm.
No it wasn't, Advent even somewhat conceded (in the Crado thread, she was like 'I'll give you Sylvar, but Crado?'). It's pretty obvious she was somewhat exceptional.