Just to provide a counterpoint. I'm in the process of buying an '11 M3 to be my DD. I have a 911 Carrera S that is my weekend car and wanted something more practical and inconspicuous to drive to work. I made a brief and unsuccessful experiment with a lesser car for my DD but missed the Porsche too much while driving the daily driver. So here I am coming back to BMW after letting my last one go in 2003. I think it will be a great blend of fun to drive, precision feel, anonymous styling and (occasional) practicality. I will need snow tires in the winter and somewhat cringe at parking it outside (# cars > # garages in my household) but I will get over it.
Just trying to provide a difterent view. Goodluck with your decision.