When customizing a fighter in Soul Calibur 5, upon choosing your preferred weapon (or soul), the next prompt is for the height of your character. There are 5 choices, and one of them is selected by default and marked with a star. This default height is different for different weapons, and the text claims something about that being the "optimal" height for fighters of that weapon.

What does this mean? What does height affect, gameplay wise? What downsides are there for picking a height other than the recommended one?