It helps, but don't expect too much. The steering feel is a little more direct, and the car seems to absorb road imperfections better (for a tiny margin). With the rear 'ARB', the car turns/rotates a little better when going around corners.
If I remember correctly, the installation was a bit annoying because you have to put the bolt at a certain angle through the hole, and when you try to put the nut on, you don't have enough space because of the ECU cable.
Edit: i see now you have a hybrid. Probably has different design. Sorry for noise...
It wont be a gamechanger but the driveability of the car should be better and more direct....especially regarding the fact that the Swift isnt a very stiff car.