Cruise control

Am I misunderstanding ACC? With good old-fashioned CC, you set the speed of your car, and it will maintain that speed no matter what happens in front of you. With ACC, the car maintains the distance to the car in front, so if it slows (like, maybe because traffic ahead is slowing), then your car also slows (I.e., doesn’t carry on at the same speed, ploughing into the car in front)

This seems like A Good Thing to me….

Correct ... that's what the A means - Adaptive.

Some ACC systems work better than others. ACC in VW cars tends to work very well; the one in the MG4 is a little "coarse", as though it is underdamped so it approaches the vehicle in front quickly and then slows down rapidly, then is slow to pick speed back up (e.g. if you move to the next lane to overtake). The control loop (PID) parameters of the MG4 ACC system need improved.

Had some software updates for the first annual service yesterday (I mentioned jerky cruise control along with half a dozen other issues) and I have to say it's a lot smoother now, more properly damped. Only tested on A roads so far but look forward to trying out on the next motorway trip. It now feels like something I could use, rather than something that's annoying to me, passengers and cars following, due to the jerky 'brake tapping'