High Roll for slick surface.
I am not either of the guys you mentioned, but I would run high roll center on a slick surface because it has been my hands on experience that the higher the roll-the more planted the tires become-hence the more mechoncal grip you produce. After running both front and rear high, you can slowly lower the end that feels too planted-no matter what springs, tires etc you use.
Its a subtle thing to feel. Roll centers arent the easiest thing to feel till youve actually changed it and nothing else and know what it does on your car.