Just about 5 minutes ago, I was driving down a road with moderate stop and go traffic (autopilot engaged), and TACC either did not react quick enough to a car in front or didn't react at all. The collision warning beeped and I slammed on the brakes, and I'm sure it also triggered automatic emergency braking, and this is the first time I've actually had to slam on the brakes to the point of getting ABS to activate. This sounds very similar to the P90D owner who rear ended a vehicle recently with Autopilot engaged, and nothing like this ever happened prior to 7.1.