Takes some getting used to but its better
I've had my M5 (E60) since May 07. I have to admit that I think the 7-speed SMGIII is superior in the M5 & M6 to a 6-speed "manual" with a clutch peddle. There is no doubt it is a faster system, mated perfectly with the v10. We had a chance to push both M5s and M6s at the Advanced M School at the VIR last month, and really liked it in spirited driving. Once mastered it is very smooth in normal street travel too.
I would never give up the 6-speed in the Z8 with the torgue of the S62 motor.
As far as I am concerned, driving one of each gives me the best of both worlds.