Same unit on both guitars, the difference is mostly due to scale length. The longer the scale length, the more tension it takes to bring the same set of strings up to pitch, which pulls harder on the vibrato causing the spring to have to work harder and this in turn also takes away some of the responsiveness.
Sting gauge also has an effect.. Bigger strings have higher tension and this takes away some of the responsiveness of the vibrato, making it feel like there is not that much movement.
