My car with radar cruise and camera based lane centering: can go any speed, doesn't need a leader, handles terrible conditions (notably it sees better than I can during night time rain with glare from on-coming traffic), comes to a stop, starts from a stop, and handles some pretty crappy lane markings.

It don't handle sharp corners and doesn't auto-drive. It does, however, take 90% of the effort out of the place I spend most of my driving time - highways.