Right, if I had to condense my issues into something more constructive it is just that: if regulators want to pursue a mandate for these systems, they should also work on establishing testing criteria and specifications that cover the many different conditions drivers face and reduces variation between manufacturers as possible. Not an easy task.
To give a quick example: another commenter in this thread states that lane assist only kicks in at 35mph. That is true in some models but not all which could lead to some nice surprises. Further, the speed limit in NYC is 25mph so it's not unusual if the road surface is decent to be cruising closer to 30. Unless there's a threshold for activation, you might be walking a fine line between "safety on"/"safety off" and any resulting corrections it might make.