Man, I would love to have both. And an M3 E46. They are such cool cars. And then, whenever I hit this situation, I would have the perfect answer: why are you limiting yourself to one, dude?
And why is the choice the "onesie" vs. the M3 anyway? If the M3 is "too slow, too heavy" isn't a 911 lighter and faster than the onesie? He better dump his onesie now, before a new one comes out, and buy a 911.