Obi-wan is clearly the greater duelist while Satele is clearly the greater force wielder.
Here's how their two edges stack up against eachother. Kenobi, while possessing a viable offense in the form of Ataru, is still a more defensive fighter than he is an offensive one. That being said Kenobi is not going to attempt to power through Satele's offense. Satele on the other hand has greater telekinetic strength, and could use that to subdue Kenobi, and if Kenobi somehow breaks her defense before she could do that, she could probably still catch his blade.
Satele Shan as a lightsaber duelist would be around Aryn Leneer level. When just glancing over her battle against Malgus in the hope trailer there are many factors that people fail to recognize. During the second half of the duel (after the toppling of the tree) she changed her tactics of how to fight Malgus and instead fought him in the exact same manner as Aryn Leneer did, until she was disarmed. And her being disarmed was not a bad showing on her part but a showing of the inherit weakness of a saberstaff. Remember even the master duelist Darth Maul had his saberstaff cut in half. That being said a weakness is still a weakness but in Sateles case this weakness is actually a strength. As soon as she was disarmed her first response was to catch Malgus's lightsaber with her hands, gaining a massive power boost in the process. And not only was she using tutaminus to hold a lightsaber blade but she was having a contest of sheer strength with Darth Malgus, him pushing with both hands on his end of the lightsaber while Satele pushed with both hands on her side, while simultaneously using tutaminus to hold a lightsaber blade. Therefore it is my belief that any character with less physical strength than Malgus would be pushed back by Satele and not only would she drive them back with physical strength, she would be gaining a massive power boost in the process which almost guarantees victory.