Had driven a 6MT 545i for the last six years, and believed I wanted a 6MT ///M car also, but now that I have the SMG, I am getting used to it and believe that it was the right choice. One thing to keep in mind is the speed of the shifts is directly related to the throttle position. The actual programs (S1-S6) have some bearing, but the major influence is the throttle position. Thus, even in M-mode, S5/6, you will still get lazy shifts if you are using light throttle to accel leisurely, and in P400, Comfort, S3, you will get quick shifts if the throttle is floored. Even in D mode on the freeway loping along in 7th gear, if you need to pass and push the pedal, you will be in 5th in no time blasting your way to 100mph. The SMG is certainly smoother in all situations than I ever was with my left foot. The rev-matching blips on downshifts are sublime.
2009 M6 Coupe, SMG
2004 545i Sport, 6 MT (Sold)