Different cars here people. Pure full-tilt sports car vs. more conservative upright 2+2 sports coupe. Both hot, both appealing but the M4 will still feel more refined and the Vette will still be the better pure performer. The distinction will certainly be less than the current gen of the two cars, however.
Audi S6 * Audi S3 * Porsche Cayman GTS
--Former BMW M3 owner