Freelancer's input polling is tied to framerate. At a solid 60 FPS, you have up to 16.67 ms of added input lag. At a solid 120 FPS, you only have up to 8.33 ms of added input lag.
Turret turning is a fixed rate based on the turret's equipment definition. Input lag is a separate thing entirely and affects all input, not just turret turn rates.
