Not a fan. Ive had it activate 3 times for really no hazard ( low hanging leaves) and its not a subtle brake application. With the back up camera, audio plus visual alerts and the good old fashion watching what you're doing, i could definitely live without this feature.
It is an emergency braking feature which is why it is not gentle. It is not a autonomous driving feature, it is an accident avoidance feature. If your car is being set off by objects then it is going to work as designed. It gives plenty of alert and then brakes when the driver doesn't respond.
Alas,
@Director's situation is quite different. How it detects foliage causes things exactly like he's experiencing.
I don't have a situation where I am driving through/near foliage in reverse on a regular basis, but, a week or so ago, I was on a photo shoot and pulled into a grassy lot (wild grass a foot high). I couldn't back up to turn around without turning off RAB. The car kept jamming on the brakes because of the grass.
It was quite unexpected, since it wasn't solid, but, I guess the way the sonar bounces off of it makes it look like a nice big object I'm backing into. It's weird. Suddenly, the car instantly thinks something is there, in crash distance and simultaneously sounds the alert, draws the red boxes and slams on the brakes. Noth...OBJECTBRAKE... out of nowhere.
Sadly, other than mowing/trimming/parking elsewhere, there's no solution other than turning off the system. I couldn't even crawl into them like I can crawl up to the wall in my parking spot at work.