1. at low levels it will NOT save you, don't waste your time
2. you can't choose which level of slowfall you wish to use(but they should really make it like the stances)
3. just as slowfall affects your falling speed, it ALSO affects your rising speed.
EX. for quests like reaver raid, and bastion, where you get shot up, slow fall will act more like slow rise.
so in bastion, if your wondering why you can't get even halfway to the switch, try turning your slowfall off