Eh, boring is relative.
Put your average person, even average car enthusiast in an S5 vs M3, and they will get faster lap times in the AWD car. They are slower in perfect conditions with pro drivers, but not by much. Once the 3.0T goes in the coupe, I would venture to say they won't be any longer.
Also, any weather at all, outside of ideal, the S5 wins, all day long. Cold dry roads, rain, full on snow etc, the S5 will be more fun, all year long.
Not to mention the interior.