I'm running the Comptech 22mm on my Accord and I saw a difference instantly.
There seems to be less body roll around turns and if you loose traction in the rear, The bar will make the car recover faster.

I had a Cusco front lower bar on my Civic Si and didn't feel any difference.
It did however protect my Oil Pan once from a wooden block
Bent the bar a smidgen and chipped the paint.

I would think you'd see more of a difference with a strut tower bar then the front lower Tie.