Quote Originally Posted by Braindead_Paul
Since I always level up to beat the optional bosses (if there are any) and try to have EVERYTHING (best weapons, all summons, all spells, etc.) before ending the game, the final bosses are quite easy in every FF.
I assume you've not played V then? There are no optional bosses of such calibur as to warrant leveling which would make Ex-Deth easy as a result of said leveling. The closest you're going to get is Bahamut, and if you just played through the game without taking time to level, you can beat him when you reach him. For that matter, if you do everything there is to do save leveling for the sake of leveling, you still wouldn't be of such a level to make Ex-Deth a cake walk.

Ex-Deth is certainly beatable using gil-toss, in the same sense that Doomgaze is easier in VI with vanish/doom. Without cheese, Ex-Deth is easily the hardest. (A statement which often holds true in general for many parts of V, as your class selection warrants even a little bit of forethought, as opposed to the fixed progression and improvement in many of the FFs.)