I just like to razz the people that keep saying that SMG owners just buy them because they don't know how to drive a manual. 99% of them don't have a clue what real driving is.
For most of the same reason you list in your post I don't drive my BMW at the track any more. Its simply not a fun car. Its a GT car for the street, not a track toy. Its to heavy and big.
However, with the lotus the two things I find myself missing from the BMW are the wider powerband and SMG. Once I got really used to left foot braking all the time is sucked to have to go back to using the damn clutch. Now all I end up thinking about is the time I am losing by not being able to ballance the car as well as I could if I didn't still have this archain interface.
It think another part of it is the Elise like your S2000 isn't exactly a slow reacting and forgiving car like your E36 or my E46. You really, really don't want to make a mistake with your cornering in either of those cars.
Manual gearboxes, the rotary dial of cars.