Hypersmurf
Moderatarrrrh...
Ranger REG said:The feat mention if you're using light weapons, not "fighting/attacking as if you're using a light weapon." Physically, the quartertaff is a two-handed weapon. It just so happen to have an extra feature, the same way certain polearms have an extra feature (does double damage when set against a charge).
The text of the Power Attack feat states "Normally, you treat a double weapon as a one-handed weapon and a light weapon. If you choose to use a double weapon like a two-handed weapon, attacking with only one end of it in a round, you treat it as a two-handed weapon."
So it's not just for TWF penalties that the off-end of a quarterstaff is treated as a light weapon; it's 'normally' treated as a light weapon.
Unless you're using it as a two-handed weapon, it's treated as a light weapon, and thus can be finessed.
-Hyp.