I have driven a few of them at one of these test drive days an i didnt really like the 4S that i drove.
couldnt stand the slappy paddle gearbox (well, thumbs), manual woulda been far better, and didnt feel like it needed the 4WD at all. those were my main gripes (oh and it was a vert, looked gash)
i just felt a lot happier sitting in the driver seat of the 2WD one
if you need to drive a 911 every day rain or shine then i supposed the 4WD is mroe sensible, but normally theyre weekend cars anyway that wont be used in tose situations, in which case the 2wd grips fine.
hell even the GT2 has full traction in 1st gear so i dont think the carerra2S will struggle... lol