Well to be fair, while IX is remarkable in it's translation and localization compared to its predecessors and the turn around time from the Japanese to English release, I've heard it still misses a lot of nuances which became more apparent with Dissidia, apparently Kuja had a more "lyrical or poetic" dialogue and liked using music and theater puns in his speeches and the English toned it down. I've heard there were some other issues with the translation but I can't remember what sections it was in but considering the game had a six-month translation/localization window compared to its PS1 brethren and even though FFIV and VI had similar or shorter time frames they didn't have the sheer volume of text that IX had; the fact it had few mistakes and made sense is a testament to the localization team's effort and hard work.