Want a lighter M that handles well, but has a real M motor, get a Z4MC, the ugly ass-bastardised 1M is no faster. It's a bit of a downgrade from a M3 to a 1M IMO. I had the choice and went M3. Nothing the 1M has (if it was better) can make it better than the E92's glorious motor (forget the rest).
Current: 2012 C63 AMG PP | 2012 F25 X3
Past: 2008 E92 M3 | 2009 E90 335i | 2007 Z4MC | 2002 GTI 1.8T | 2000 Celica GT-S | 1999 328i | 1990 Corrado G60