__________________ "Vader's pulse and breathing were machine-regulated, so they could not quicken; but something in his chest became more electric around his meetings with the Emperor; he could not say how. A feeling of fullness, of power, of dark and demon mastery -- of secret lusts, unrestrained passion, wild submission -- all these things were in Vader's heart as he neared his Emperor. These things and more."
Really, I don't have too much of a firm opinion on Tythy ^^ I do tend to assume the most powerful jedi of a particular age is fairly powerful, but I've yet to bother to buckle down and look at all the data. Especially as, as main character, I expect it to get new feats semi regularly.
Well the HoT is more than just fairly powerful. Try "immense"ly powerful. And calling the the most powerful is maybe underselling her a bit. She's deemed the most powerful Jedi in the Order for a looong stretch of the story and is continually improving at a substantial rate.
And I doubt we'll get much new content and feats for her anytime soon. Bioware seems to be focusing on new flashpoint and planets instead of class content.