Its a pain in the ***, I don’t just set my cruise and follow others 3 truck lengths back. There’s always slower moving vehicles regardless of the highway or interstate and it wanting me to slow down all the time, it’s just annoying. On my wife’s lexus you can’t even disable it, just minimize the car lengths and it still drives me nuts.
Of course there are often slower vehicles. But if they're taking up all available lanes, you have to slow down anyway. With a normal cruise, that means fiddling with the controls or tapping the brake first and then matching speed with the accelerator. With adaptive, it handles all that for you, and if it slows down where you don't want it to, you can override it with the accelerator. It will auto-resume the moment you release the loud pedal.
When I first drove a car with ACC back in 2012, it took a while to learn to trust it and become accustomed to it. Shortly thereafter, I took that car on a 2000 mile road trip (PA to FL and back) and quickly decided I'd never buy another vehicle without it, at least not one that I would take on that trip regularly. I do occasionally drive a vehicle on half that trip that only has regular cruise and find it a PITA to have to fiddle-fart around with the normal cruise.
FWIW, I generally set the ACC to 10 over the posted limit. That doesn't make me the fastest vehicle on the road, but I'm certainly not the slowest either.