Not sure if SMG is setup the same way on the 650 as the M3. Is it possible to
completely disable Stability Management/Traction Control? And is there a shift-speed selector? The M3 has these. If the 650 doesn't, the SMG would basically suck. The ONLY way I would drive my M3SMG was to first disable electronic aids then select P6 on shift speed. It was an absolute ball to drive in that mode. Much faster up/down and more consistent shifts than any traditional manual (there's a reason all top series race cars use them). Took some miles behind the wheel to really learn how to use it. I put 75,000 miles on mine (SMGII) with no problems.
I suspect SMG would not be much fun on a heavy car with somewhat numbed-down suspension/steering such as the 650. I drove a 650 cabrio 2 nights ago. Unfortunately, with an auto trans. Nice cruiser I suppose and gobs of torque. But it felt like driving a Camaro Z28 with a big block ....
