I have a standard suspension E90 M3 including 18 inch wheels (though wider ARC8 18 x 9.5/10.5) and recently drove a ZCP E92 M3. To me, the ZCP car felt better in terms of handling. The suspension felt tighter (it was on the middle setting) and the steering felt a bit heavier and more reassuring. I preferred it. Maybe it was the lower profile tires and slight lowering.
Made me think about buying a set of H&R Sport springs for my E90. I would not go to 19 inch wheels, but I will go wider on the tires to 265/35/18 and 285/35/18.