"Tesla's Dual Motor Model S is a categorical improvement on conventional all-wheel drive systems."
"Conventional all-wheel drive cars employ complex mechanical linkages to distribute power from a single engine to all four wheels. This sacrifices efficiency in favor of all weather traction. In contrast, each Model S motor is lighter, smaller and more efficient than its rear wheel drive counterpart, providing both improved range and faster acceleration."
We'd rather of seen the Tesla Model S P85D in some deep snow, but at least there's some tire spinning and even a bit of drifting action.