Okay so this may be a taboo topic, but someone had to bring this up sooner or later. I've now spoken with three Model S drivers who each admit that on long drives Autopilot keeps them refreshed - but strangely also sometimes induces drowsiness similar to the effect many people experience while riding in cars as passengers. And two of those people told me that switching off the auto-steer function instantly restored mental alertness. Sounds ridiculous I know. I wonder if this drowsiness effect is common - if so I would not be surprised to see nobody on the forums admitting it, out of a (perhaps misguided) fear of either being lectured by self-appointed safety-nags (you know who you are) or worse, having their posts brought in as evidence in some future civil action after a car accident. But the kicker - I've spoken with a Model S owner (no I will *not* identify that person in any way so don't ask) who admitted to me privately that on an hour long drive recently they briefly nodded off three times coming home late at night from a party. This person claims they don't think they were asleep for long - but of course how would they know? They didn't know how fast they were going - somewhere between 65-75 mph they estimated - and of course the "nod offs" couldn't have been for too long because they never awoke to find themselves parked on the freeway with their emergency blinkers after "hold the wheel" failed to get their attention. This is a person who doesn't drink or use any drugs, who's in good health. However, the owner may have used autopilot to travel in a situation in which they otherwise would not have - coming home alone late at night from a party (the person is normally an early to bed type). The key question none of us can answer is: what is statistically safer? A sleepy/drowsy barreling down the highway using autopilot, or an awake driver not using autopilot but who is subject to all the "human errors" and attention lapses people routinely make while driving?