Anti-roll bars are best used on smooth, and high-traction tracks only.
If you must use one on a bumpy track, try to use a very thin one.
Adding an anti-roll bar, or stiffening it, reduces traction at that end of the car. So it feels like the opposite end has more grip.
If the track is smooth enough, it also makes the grip level feel more consistent.
Anti-roll bars reduce body roll in turns, so they make the car feel more direct, and make it change direction quicker.

Stiffer Front
An anti-roll bar at the front of the car reduces low-speed steering. The turning radius will
be larger, but very consistent.
It reduces 'hooking' by preventing front end roll.
The car will have more rear traction in turns.

Stiffer Rear
Adding an anti-roll bar to the rear of the car gives more steering. the car steers tighter,
also at low speeds.
On a very smooth track, it can make powersliding easier. It can also make powering out