I think acc is one of the best bits of usable tech on my car. I use it everyday.
With normal cruise you often need to keep to turning it off/on because the driver in front who’s not using cruise at all will struggle to keep at a constant speed so eventually you’ll catch them up which means you’ve either got to lower your cruising speed or overtake them.
acc gets rid of this problem. They slow down, you slow down. They speed up, you speed up.
Its not the end of the world if you’ve got to keep switching it on and off. You get used to it if you use it regularly but I think acc takes over that decision giving you one less thing to think about.
It can be irritating when another driver jumps into the space that your car has left but as long as you’re patient the car will do its thing and re adjust its position. The worst time is when someone pulls in front and then slows down. I usually just disengage cruise at that point and either wait until they’re gone or go past them and take up a new position further up the road.
My car came with it as standard. I would probably only pay extra for it if it was around £250 or less. Any more than that and I’d struggle to justify the cost. That’s assuming the car came with normal cruise as standard.