This past Sunday, I got to drive the Z on its first AutoX with the swaybars on it. I had run a test and tune beforehand, but it was cold and raining.
I set the bars to medium-stiff on the front and medium on the rears. It felt great. Turn-in was much crisper than last year and overall grip was up. Tires are the same, so, if anything, grip should have been down.