They were both interesting, though Gabranth got the most story and screen time.

Voted for Drace because I suspect that being a woman she had to work harder to get where she was (as there are allusions to the Empire being racist and probably more than a little bit sexist too). She also seemed to have kinder virtues and a sense of honour that extended beyond her own self-preservation.

It would have been so much greater if we had been able to see more of the background stories of the Judges (and all the characters in general). Like:
Why does Vayne seem to have a particular malicious hatred for Gabranth?
How close were Gabranth and Drace?
What was Judge Zargabaath really like?

That kind of brings up the whole essence of what frustrated me about the game. Enjoyed the gameplay and world... story not sooo much, but it could have been strengthened had the depth of the characters been explored that much more. Because I did think they were interesting!