"Impact" as in an inevitable crash. I like it because it has unquestionably caused the avoidance of two cases where my car would have hit something. Once when I was merging onto a freeway and the car ahead of me basically brakechecked panic'd at the last second while I was briefly looking over my shoulder at the traffic I was merging into, and the other when a friend of mine borrowed my car and nearly hit a deer. Both cases the AEB kicked in, the car came to a very aggressive halt, and the crash was avoided. Yes, the AEB has kicked in at other times, but on the whole, it's been great and I appreciate having it. Probably other manufacturers have different implementations and different experiences. Mine is a Tesla.