I donno. I drove both the 2S and AWD turbo at the Porsche school and the chasis dynamics of AWD are a little different. Its amazing when you're pushing the front hard though a turn and you can feel the AWD adjusting to optimize the traction. Seems like the AWD is a superior technological solution, but for the added weight. Under normal unpredictable street driving conditions (rain, sleet, etc), seems like AWD would be superior. The electronics are so sophisticated they don't feel different except at the margins of traction, where the AWD is superior.

 

I have a friend with a 4S and he hates that he can't break the tires loose. AWD = better handling/traction control but less fun/challenging to drive. Choose wisely the one that fits your driving style the best.