Yes, The Exile is very strong, as is Revan, who was her instructor for a long period of time (informally). Revan is not canonically dead yet which shows VERY strong force powers, compared to the likes of The Emperor, maybe better, maybe worse, I'll make a proper list tomorrow after I've researched canon and all that good stuff. I'm not denying that any of these people are weak, Nihilus, strong. Sion, strong. The Exile, strong. etc..
Let us go through the canonical greats that Revan has achieved: (facts)
- He led the Republic / Jedi to victory against the Mandalorians, defeated the Mandalore, destruction of Malachor V and this gained him the nickance 'Revan the Butcher'
- Tracked down all of the Star Maps, TWICE; defeating numerous strong foe along the way.
- He became Sith, warred against the Jedi and was winning by a very long shot before the betrayal.
- He was credited by the Jedi Exile herself that he was a large factor in why she was so successful (teachings)
- He survived over 300 years of the Emperor feeding off of him, and from KotOR canon, where Malak feeds off Jedi Masters and Knights, he exclaims how he draws the power from them but they will eventually die (short term) which shows us how strong Revan is.