Edit: Just looking at a Honda manual online[1], it says: "ACC may not recognize motorcycles or other small vehicles ahead of your vehicle". That's more than a little worrying.
[1] https://techinfo.honda.com/rjanisis/pubs/om/JA0606/JA0606O00...
It also uses that camera to dip the headlights, which is often tricked by two lights close together (reflectors on bollards or traffic cones). It's also has to wait to see the headlights, where as I can tell they are coming a short time before.
A really rolling road (Arizona has some of these) where the car might be one "roller" ahead of you but look a lot closer, then your car hits the brakes at the apex with a car tailing you.
The biggest issue is that it ignores stationary cars, so if you come around a corner to red traffic lights it would drive straight into any stationary cars. Which is why I only really use it on the motorways (highways).
That being said it feels very futuristic having a radar in your car and makes driving on the motorway a lot more pleasant. However I now seem to spend the brain cycles I was using on judging speed imagining up bugs that could cause me to accelerate into the car in front :/