I actually did finish US 7th saga once. I think I used Lux and Esuna.
The whole game always struck me as a great concept that was never fully fleshed out. Like it starts off really cool, a refreshing departure from other RPGs of the era, but by the time you get to the part where you're chasing one of the other adventurers around (you know, when they get to the rune before you), the game seems to completely run out of ideas.
And if I remember correctly, you lose your partner for the last dungeon? I think that's why I only finished once. Every previous play through, you get to the point where you're really relying on that other character, then - BOOM - have fun alone, sucka! I also feel like if a person were to choose one of the magic users as their primary, the game would at this point become not just insanely difficult, but actually impossible.
I guess technically that's a problem that a good balancing patch could take care of... But then I also remember the ending was pretty lame and unrewarding.
Oh, and the music... My god, the music. This is one game that should just say "hit mute" right on the title screen.