Adaptive Cruise Control is one of the best things about this vehicle for me. Yes it sucks the diesel, but it makes long drives so much less tiring, even over regular cruise control.
I hit a deer in KY in early July (boy, this Jeep can take a hit). Knocked out the ACC (which knocks out the reg cruise too by the way). Drove the rest of the way to NC manually, then drove from WNC back to Flint, MI. My mileage shot up to 31 (almost 32mpg) vs. a steady 28 with ACC (@ 78mph). But I was so damn tired, I didn't care.
We dropped the 3.0 off at the repair shop and took my bride's 3.6 to NJ to tow the bike to NJ for a race weekend. Really missed the ACC and blind spot markers on that trip.
With ACC, I can drive 800 miles at a crack and not feel too worn out from it. Tired, but not broken. Well enough to hop in and do it again the next day.
The ACC unit is $1300, and they were back ordered at the time. The repair shop was able to hook up my old one, and it seems to work fine (the plastic where the wiring harness plugs in was what broke, not the radar unit itself) . The part is in, so I'm going to go in soon and have the new one installed. It is such a new car, I don't want to take a chance of the old unit failing down the road.
By the way, it will bring the car to a complete stop, but it only holds it for a few of seconds (3 to 5) before is shuts off and effectively says, "Hey, you need to drive now!" I kind of wish it would hold it longer to give traffic a chance to get going again. The bad thing about traffic is that the ACC leaves a friendly gap to the car in front, and this gap invites everyone to slide in right in front of you, potentially leaving you at a standstill.