While I think Carthage might be overrating Shaak Ti, I do see where he is coming from. Shaak has better speed and skill feats. She moved fast enough to kill multiple MagnaGuards at an instant before they could react, while Satele wasn't capable of doing the same to three faceless fodder Sith who either just got kicked by her or perried her attacks before getting cut down. Shaak Ti also overwhelmed Galen Marek by virtue of pure skill on neutral ground during their fight. Only later did she use the enviroment after Galen started using the Force, and even then she was winning. Felucia was geared twords the Dark Side and thus a place like that could offer a Dark Side Nexus of which Galen could amp from. An amped Galen>Malgus during his second battle with Satele. And Shaak Ti was shown to have more skill than Marek almost killing him at one point, while Satele was being overpowered by Malgus. Now Satele is more powerful, but not by a huge amount. They both blocked Lightsaber strikes with Tutaminis, though Satele did a better job, though to be fair when Shaak used Tutaminis she was exhausted and her assailant was stronger than Malgus. Shaak Ti's Kinetic and TK attacks are comparable to Satele's. Shan made tons of rock crumble, while Shaak Ti moved a ton of rubble with ease during her first battle with Grievous. Satele TKed Malgus and Shaak Ti TKed Galen Marek and crushed him with Kinetite. So I'd say:
Sabers- Shaak wins 7/10
Force- Satele wins 6/10
All out- Both win 5/10, or Shaak wins 6/10.
It'll be an epic battle either way.