Description: The sway bar, also known as a stabilizer bar, is made of spring steel and mounts to the frame or unibody. The ends of the sway bar connect to the lower control arms.
Purpose: The sway bar helps reduce vehicle lean during cornering.
What people talking here about sway bars is actually replacing stock sway bars to aftermarket ones. The reason is: aftermarket bars are thicker in diameter and stiffer. This leads to a reduced body roll when cornering.
I just replaced mine, both front and rear, on Accord 2003 I4. The front one was not really that much thicker then the stock one 27mm as opposed to 25.4 mm. The rear one was a different story. 19mm versus 13mm. Huge difference. I also got my ride lowered with TEIN SS coilovers and installed front strut bar. All my bars are made by NEUSPEED.
Have I noticed a difference? Hell yeah!!! The car stays straight when I take corners and body roll reduced I would say by 80%.

Hope this helps.

Cheers