Adjusting Front Roll Centerf

Has anyone tried adjusting and track testing the front roll center on thier cars? I am fitting new upper arms and ball joints.

My front end is currently set up with 1 thick, 1 medium and 1 thin spacer washer under the upper ball joint (the Coleman kit comes with 1 thick, 2 medium and 1 thin spacer).

I am interested in what results people have got from adjusting the roll center and what settings they setttled on.

Thanks, Kel.