I NEVER wear it down! My hair (currently waist level) is too long to wear down. It's always up in the home, outside etc. Hair naturally falls out and I dislike seeing my long hair on the floor etc. Also, if I left it loose my kids would always be tugging at it. Furthermore, if left loose my hair goes all bushy, messy and notty (dunno if that's a real word LOL).
In my carefree days as a uni student I left it down but not anymore!
ITAHaving long curly hair I've become a pro at wearing it up. Sometimes I just have to. It can be a horrific jungle sometimes. Like they say "neccessity is the mother of pony tails."