Originally Posted by jvitas
Gerahead999 is absolutly correct about the differences between DCT and SMG. However, they both contain gears and clutches. I've been involed with clutch and gear box designs for over 30 years and you can't design away the problem completely. BMW did a phenominal job with the DCT and the computer control is extremely precise, but this is still a passenger car transmission, albeit a very good one, but if you abuse it it will fail. So if shifting in S6 is your thing, do it. But if you think its improving your lap times you're kidding yourself. Does it change the speed of the car? I doubt it. Does it put extra strain on the transmission? Absolutely. Does it unbalance the car? Sometimes.
Maybe a little. The higher the DCT setting, the bigger the "surge" when shifting, so more of the inertia of the engine is converted in forward thrust instead of dissipating it as clutch slippage and heat...