I addition to what Kristoffer said (and he should know what he's talking about!
), IMHO (and I'm no designer, this is just my impression) you have to look at the big picture. Special powers need special weaknesses so that overall result is balanced. For example, Caelians can fly, but their combat performance is weaker than that of a basic human.
[ March 21, 2004, 14:11: Message edited by: Teraswaerto ]