Re: Not an "autopilot"
"It was too easy to lose concentration when the CC was doing the work - not a good idea on a 70 MPH motorway."
There's plenty going on around you. ACC is great inasmuch as you don't have to worry about having to regulate your speed, but that simply gives you more time to look out for other drivers hellbent on killing everyone around them.
Then again if you're losing concentration with CC on, you ARE one of those drivers. Don't touch the radio.