I am always holding on to the wheel. Yet it frequently ‘Ayrton’ asks for me to make a small steering input to confirm I am paying attention. In one case it took autopilot away even though I was providing the required steering inputs. The message was that it judged me to not be paying enough attention and it disabled autopilot until the next drive. I needed to stop, go into park, open the door and then resume the drive to get autopilot back.  So even in a case where you are holding on to the wheel and providing asked for steering inputs it is still optimized to be cautious and err on the side of asking for extra attention. I have not figured out what additional metric it used in that case. Or if that behavior has now been modified. The little tweaks in the upgrades to autopilot are worth reading the release notes for. That can be frustrating and must be a pita for Tesla to get through legal etc. I would compare the danger of the new tech to what people faced generations ago when the went from horses to cars. You learn fast what is working and what does not. The documentation from Tesla in terms of instructions and warning must be understood. They can make you read but they can’t make people understand. But that applies to everything. 
There are some situations like traffic jams where it is awesome and the economy of the electricity shines. Other times I am not going to let it drive. No way.  Looking forward to using it in the snow. And yes I double checked this was a Tesla thread. And yes I named my car. If I had a son ...