Just a personal thought...
Squall, in game, would easily defeat Seifer, due to his limit break. Assuming that a) they had made seifer able to gain multi-hit limit breaks and b) not made Seifer the villian, who obviously couldn't be more powerful then Squall in game cause Squall is indeed the hero, I think they would be very close to equal. Squall has a far more damageing gunblade, but Seifer is
very agile, so the fight would be a tie, removing all cheap tricks on both sides.
I like em both. *shrug*