If you look at the acceleration data (not the old car mag DSC inhibited data), you'll see that against a typical fast manual driver, the SMG will gain ~0.1 second/shift. Now judge how important it is to you to get to 100mph in about 0.2 to 0.3 seconds sooner. Balance that versus the fun and control of shifting yourself (and being able to control the clutch yourself). The answer will lie within. Up to legal limit speeds here in the USA, assuming identical conditions, etc, at most the SMG car will be ahead by 2/10ths of a second (assuming the SMG driver is capable of an S6 mode punch and modulate launch to net a good 60' time -- something many who've driven a manual for decades can quickly achieve with the 6spd).
Then ask yourself how often you're going to be doing WOT runs to illegal speeds. How often are you going to go to an HPDE event where you can really enjoy the SMG?
In any event, if you choose the SMG, price in a new clutch/pressure plate/throwout bearing/guide bush, and consider using All German Auto's
pivot pin design. The t/o bearing on the SMG sees a really high duty cycle, so many owners have experienced early t/o bearing to guide bush galling/wear (i.e. see the threads on the board covering the issue). Just assume any SMG car needs a nice new parts, bite the bullet, do the work, and enjoy a butter smooth SMG experience right from the start of owning the car.