As I said these two cars are two total different animal. Sport sedan vs sports car is not fair. 997 you can hardly fit someone at the back. You hardly have enough space at front trunk. BMW M3 can do all these no problem. So M3 is not bad for what you pay for.
Need space and good performer get the M3
Need no space and excellent performer get the 997
Despite the speed and everything. I find FR is easier to drive than RR car. Heck, I'd be going faster in the M3 than C2S.
If you are too afraid you can always get the C4/C4S
