Once rolling the M3 is faster than the S6. 100-200 kmh for M3 is 10.9s while for S6 is 11.3s.
The M3 shines at high speeds.
16 Audi A6 3.0 TFSI
11 Audi RS5 Misano Red--sold
08 E92 M3 Jerez Black 6MT--sold
08 E92 335i 6MT traded in for M3