ZCP is overrated. I have it.
I've heard that 18s are better for tracking, but they look noticeably smaller than 19s.
2011 1 Series M Coupe VO M3 vs 1M Comparo Review
2011 M3 E90 DCT ZCP (sold) * 2010 335i Sedan (sold)
2005 M3 Convertible (sold) * 2003 325i Sedan (sold)