It definitely differs between implementations. I hear Distronic Plus on a W212 Mercedes (so 2009-2016 E-Class) was fairly good for its era, with smooth braking, but I'm biased because pre-touchscreen-hell Mercedes cars are something I have a soft spot for (so pretty much anything made before this decade, really - they kept touchscreens out of the equation for longer than Audi at least). On W211s you could get regular Distronic, which didn't come to a complete stop, it was only meant for highway use. Also all these systems were optional back then, so you can't buy cars blindly. Hell, I bought a 2019 C-Class being pretty sure it had ACC and it... did not.

I unfortunately can't give any advice on Japanese cars, I've only owned a Subaru. The ACC in that was a bit janky, though it never hit anyone so it definitely worked. Most of the time. It complained about lack of sight fairly often, since it was a camera based system unlike the radar or lidar systems most seem to use.