Already had an '07 E63 which had the current motor in it. Test drove a 2011 and felt like the same car..just different body. Besides, i hear the bi-twin turbo in the 550i is EASY to mod. Besides If i want all out speed not many cars faster than my '09 Viper (modified) on the road anyway. Don't run into many Bugatti's Veyron's

 

The new M3 is the perfect DD IMO

 

M3 4 door for one week now. lots of fun for driving to work and easy to carry my 2 kids when i have to. big thumbs up.

 

From a performance standpoint the M3 matches up with the C2S. New, a fairly loaded up M3 will be in the mid $70k range. A comparably equipped C2S will be about $40k more. Keep this in mind. Irrespective of what one can afford, value is value. No reason to **** money away. The M3 is a much better value for a new car.

The Porsche is a pure sports car. The M3 is a luxury-performance grand tourer. I wouldn't even compare the two. Cars to compare to the M3 are the Audi RS4 and RS5, the C63 AMG, Caddy CTS-V, and alike.

So...all depends what you want, but don't expect an M3 to have the reflexes of the C2S. And don't expect the C2S to have the smoothness of the M3.

Keep it in perspective however. The M3 is still one of the best all around performance cars on the planet, as is the 911. Within that narrow upper end of cars (exotics notwithstanding), however, each of these vehicles is slightly different in focus, and significantly different in cost.