My RAV4 has ACC. I was quite insistent that I had it to the point of refusing a car the dealer found and had brought to his dealership for me, because it did not have it, despite them thinking it did. I ended up getting one which had been a Toyota Fleet Car for 12,000 miles.
Well, I hardly use it. Why? Takes all the interest out of driving and makes me lose attention. It is absolutely useful in restricted lane average speed limit roadworks and things like that, but in the normal commute and drives of les than an hour, I rarely switch it on.
Funny that! Was convinced it would be a great feature. When combined with lane departure warning and collision detection, you are almost in auto pilot. But because the car is not fully autonomous you need to stay alert, and long stretches of doing nothing but steer make for a dull journey.
Another weird feature of ACC is when you 'lock on' to the car ahead and for whatever reason that car slows down over time and eventually you realise you are doing 50 in a 60 or similar. Then you have to take control in order to overtake, as the ACC does not really respond quickly enough on the accelerator when you move out to overtake. Then you are in manual for a bit until either the road ahead is clear or you feel you are in a good traffic flow, then you re-engage ACC.
In the end, it's more trouble than it is worth, for me.