Early reviews of the Model S have been published, after Tesla allowed some journalists a short guided test drive of the vehicle. Here is one:
What is interesting to me here is the "one pedal driving" comment. What Tesla apparently has done is tuned a very aggressive off-throttle regen. In the gas side of the biz, you would say that they used very little "dashpot", in other words, allowing the throttle plate to close quickly. In this case, of course, you get electric regen braking, not engine vacuum based braking.
This is interesting because many efficiency gurus actually prefer a lot of dashpot--this allows for an efficient "pulse and glide" driving style, while saving heavy regen for actual braking events.