3-4 weeks after I got my '19 signature, this feature of our car saved my ass, and likely prevented the car from being written off.
I had a video of it, but can't find it.
Essentailly, someone made a blind-left turn in front of me just as someone in the lane beside me to the left decided to [illegally] veer into my lane. (I was in the right lane, traffic in the left had stopped to allow someone to turn). I had already seen that traffic had slowed so I was slowing down when the car veered in front of me. That car then had to slam on his brakes to prevent hitting the car making the blind left turn in front of us.
Since I was already braking, I began to brake harder however, the auto-braking system must have recognized I was not applying enough pressure. the "BRAKE!" visual popped up on my HUD display, with the audible warning, and the vehicle came to an abrupt stop, about a foot from the guy in front of me.
It saved me. Big time.
To be objective, I will also tell you that it will give you false-positives sometimes. For example, if someone is turning right into a parking lot and making a career out of it, and the system senses you aren't slowing down enough, it will "BRAKE!" you (visual and audible alarm) but will not put the brakes on unless it senses you're going to hit the car.
Some others have reported that in situations like this the car has slammed on the brakes, but 12,000km in, I have NOT had this experience.
All in all, I'm very glad I have the system in the vehicle. It proved itself to me.