When completely barehanded (no weapon at all equipped) swings will still be at a normal swing speed and unaffected by this perk.
This perk does not affect Action Point costs. However the increased speed does cause V.A.T.S. attacks to execute faster thus reducing the amount of time that the player will be "locked" in V.A.T.S. sequences where they are left vulnerable.
Lonesome Road (add-on) The benefit of this perk can be utilized even more with the consumption of Rushing water, Offering a combination of +80% Melee/Unarmed attack speed.