I test drove both the normal and sport shifters before placing my order for my '06 C2S, and I thought the sport shifter was way too stiff.

But after 3000 miles, the gearbox really loosened up, so I put the sport shifter in and I love it. I think the shorter throws really transform the car, especially on the track. When the gearbox is cold, I simply shift in to 2nd gear before going into 1st gear, and that really helps a lot.