First, on Tuesday Nov 7 the car goes to the dealer along with a printed copy of the response from M.B.Doc was kind enough to post. I hope this fixes the problem. But, at the risk of sounding like I am biting the hand that feeds me, I take issue with your statement that the tranny is 100% electronic. The controls are electronic, but the insides of the tranny are a complex mechanical/fluidics system. A knowledgable friend owns a 288 Ferarri GTO which is maintained by a retired Mercedes technician. According to my friend, this guy was called in by Mercedes USA to help debug shifting problems (I don't yet know specifics but have an inquiry in to this guy) on 1999 E55s. The result, my friend claims, was an updated clutch pack which is documented in a service bulliten applicable to 1999 & 2000 models. I can imagine that the transmission fluid viscosity when the transmission is not fully warmed up, coupled with a cold ambient air which might make the motor produce just a little more power, would collectively add up to slightly faster run-up and slightly slower transmission lockup during the 1-2 upshift which would cause this problem. Even if this was the problem, I could also accept that a different ECU that lowers the upshift speed, or backs off the throttle until the motor (and transmission fluid temp if there is such a sensor) is warmer than the the original ECU used in the shift map.
Can anybody confirm the existence of a clutch pack SB and if so, what are its specifics?