>>713170827
3D has some distinct advantages:
You can get crazy with camera angles, and look at characters from any direction. Very useful with Disgaea's dramatic attack animations.
You can make more tweaks to characters without having to draw a whole new sprite sheet. For example, you can put a new hat on them, or glasses, or bunny ears.

Until Disgaea starts capitalizing on this new avenue of cosmetic customization, they really aren't living up to the advantages of 3D.