I would counter with the Rutledge: Salt of the Earth, Conscience of the Court. Or, perhaps more famously, Abraham Lincoln, who remains widely regarded as having tremendous personal character.
Full disclosure: I clerked for John Ferren and Noah Feldman was in my brother's class at Maimonides. I know whose opinion I respect more.
More seriously, there is a trend to think of lack of midot (I shall loosely translate as virtues) as somehow being an element of greatness. This is nonsense. There is a difference between being firm or principled or effective and being a jerk. While it is certainly the case that being a jerk does not disqualify one from being great -- history is full of people who did very important things and were obnoxious and arrogant. But it is hardly a prerequisite, and the belief that somehow irritating behavior produces pearls of greatness is one of the things that makes life less pleasant than it could be.