I'm still not completely clear on the terminology of what system covers what speed etc. but I was exiting a freeway going about 55 and the person in front of me stopped quickly. The system alerted with red lights and sound and I braked. I would have hit the car if it had not gone off. It did not have to do the braking and since I was going fast it may not have actually been city safety but the other system that kicked in.
I have had the lights and alert go off in town but they were situations where I was not going to hit someone. It hasn't bothered me.