The main reason I don't pick Aeris as a party member? When you first get her she does like 20 HP damage per hit. And then she's kidnapped, so you get to see how much stronger everyone else is in comparison (at that time, regardless of how gr8 she becomes later on). When 90% of battles is going to be you mashing circle and attacking, I know I'd rather see big numbers than small ones. Once you have a good party you like, you're not gonna swap in someone else because she ~might~ become great if you put in countless hours getting her best weapon/etc, when you already have a party that is mowing down everything.