A 9th level Swiftblade gains the Perpetual Options class feature:
Perpetual Options (Ex): At 9th level, you can perform even more actions with the haste spell. Instead of making one extra attack at your highest base attack bonus while under the effect of a haste spell that you cast yourself, you now have the choice of making one extra move action or one extra standard action. For example, you could make three consecutive move actions with this ability, two move actions and one standard action, one move action and two standard actions, a full attack action and a move action, a full attack action and a standard action, a full round action and a move action, or a full round action and a standard action.
This benefit replaces one of the ordinary benefits of the Haste spell, the ability to make an additional attack when using the full attack action.
If a 9th level Swiftblade under the effect of Haste uses some other option that grants an extra attack, but that normally doesn't stack with the extra attack from Haste (like the Sakkratar's Triple Strike spell (LEoF), or a weapon of speed), do they get both the extra standard action and the extra attack? Or do these effects still "not stack," even though they're now providing different benefits?