What you are describing in regards to the '6' is actually a conventional automatic tranny with a hydraulic clutch. Like many of the newer slush boxes it has some buttons or levers that allow the driver to over ride the computer to a limited extent and shift at a higher rpm or downshift ealier.
However, the F1 style shifter in the Modena and other cars like the M3, new M5, Maserati etc.. have a servo actuated clutch and a smart ECU controlled throttle that will perfectly match revs when shifting. This technology is a direct trickle down from F1 racing, hence the name duh, and is usually faster than both an auto or stick shift. It is also a bit pricey but it is trickling even futher down the sportscar food chain as I've heard, the MR2 spyder was available with it and it is currently optional on the z4.
I stick by my guns and still prefer to shift the car myself. Besides, pulling on a plastic lever will never be as satisfying as clicking off the perfect heel-and-toe downshift.
Ain't progress grand?