I rented a car that had this feature and instantly hated it. I forget the make, but if it detected you were not looking at the road for a period of time, it would slam on the brakes and release. A way to jolt you awake.
The problem was it routinely misclassified where I was looking, so I would get random brake slams which would panic me more.
I returned it after a day and asked for a new car.