I make a habit of counting seconds between cars (particularly in light traffic, which is also the only time I'm using cruise control), aiming for the standard 5s follow. At 90km/hr (25m/s), you're telling me Toyota's cruise control has a maximum follow distance of 2 seconds? That is incorrect from my experience (and unsafe from standard driving practice). Where did you get that number?

Most of my cruise control driving is on very low traffic volume divided highways. With regular cruise control, if the distance to a car gets smaller, I know there is a speed differential and I can slow down or pass, as appropriate. With the adaptive cruise control, the system as decided for me that slowing down is the correct option, generally before I've gotten close to where I would normally pull out to pass. With the long follow distance and the very gentle deceleration, I generally don't realize the system has slowed me down. This would be good as long as slowing down is the decision I want, but my cruise is generally set at the speed limit and I'm slowed by someone driving slower when the conditions don't warrant.