Obviously, we're a little late...
Anyway, I put my cross next to Brianna. Firstly, I normally played TSL as a DSM (albeit as Mical a couple of times
), so I have more familiarity with the Brianna character.
From what I could tell from my only canon playthrough (LSF), Brianna seems to be an immediately superior combatant, very useful in the early battles before hitting the prestige classes. She also has, in my opinion, a much better storyline. Mical's presence seemed to become rather redundant after a while, just another gun in the party, like Mandalore, or HK, T3, G0-T0...
Granted, if the deleted content had gone ahead, Mical may have been much
more interesting, with the holocron hunt, etc. but as it stands, only Brianna's story really seems to get to a conclusion.
It is plain that Mical was to be to the female exile what Bastila was to the male Revan, especially in light of the deleted content, but I feel the character fails miserably.
And yes, Mical's doe-like naivety wore thin quite quickly - at least Brianna had a few good scraps with Atton and Visas!