For me, I do look much younger with my hair curly, but this isn't necessarily a good thing... I have what is charmingly referred to as a "baby face" -- On my best day I look sixteen (I'm twenty-two). I'm about to go into graduate school and friends of my parents' ask me what grade I'm in. Straight, I still look young; curly, I look like Shirley Temple and people want to pinch my cheeks.
I think curls are more whimsical and spontaneous. Just another benefit of curls....someone should add it to the list.lol