Zedd himself says he chooses to be old, even though he could stay young (which I actually think is part of his penance for being so arrogant as to help Darken Rahl be conceived, but I digress). Agreed, definitely.

Given people's natural tendency to want what's bad for them, though, and assuming this applies to wizards as much as to anyone else, I can't see so many people choosing not to be immortal, if they had that power.

The Sisters of the Light/Dark are different, though, because they don't live longer, exactly - at least in the show, it's more a matter of a different temporal scale.