SMG
A bit off topic, but I just finished 3 weeks of 645 SMG driving during my European Delivery vacation. Of course it's only the 6 speed, but very different from the earlier generation SMG I test drove in a 330i last year before I ordered my SMG 645. While it does not have the exact same feel as an automatic (the same as the 6 speed in my 745i I assume), it is MUCH less harsh than the older SMG in the 330i.
During my trip, when I was in heavy traffic on unfamilar roads and focusing on the Nav guidence and the other cars, the SMG in "D" mode operated mostly like a fully automatic transmission. It did not upshift on trailing throttle when I would have expected from a fully auto trans (it holds the lower gear longer), but otherwise it was very smooth and pleasant. A good trans choice for a car if you get stuck in stop and go traffic a lot. On the level, the car does not creep when stopped (no brake required to hold still, unlike a real automatic). And yes, the car will roll backwards on an incline, more so than a regular automatic. And you park in "D" and start the engine in "N". Otherwise, a no brainer to start/operate. No doubt a lot easier to palm off to valets than my 745i which needs some starting/shifting instructions for the inexperienced!
Since my 645 had 1 mile on it when I got it, I could not use the Sport mode button during the break-in period (most all of my trip). When using the SMG paddles (and yeah, they don't do a thing unless you move the shift lever to the right to switch from "D" to "S" mode), I found that you need to fully press the paddle to get your downshift. Once in a while I flicked too lightly and there was no shift. Not the car's fault, I just needed to develop a touch for the paddles. I also learned to anticipate a bit with shifts as the non-Sport mode shift does not happen instantly when you press/pull the paddle. So, while driving twisty country roads in Tuscany, I pressed the paddle a half second before I wanted the actual gear engaged. Still a very quick shift, even in the comfortable "normal" mode.
I've read that some folks don't like that the paddles rotate with the steering wheels when they have to turn the wheel a lot (like tight turns calling for 2nd gear). However you can also reach for the shift lever and catch a gear that way without having to "chase" the paddle around the wheel. Like anything else, it only gets better with practice.
I hope the M6 7 speed SMG retains the "Jekyll" smoothness of my 645's SMG. Reading reports, the "Hyde" mode sounds like a neck-snapping rush.