The way I've looked on it on the last two cars was that it's a relatively cheap option, and the night vision from it is brilliant (to compensate for the crap reversing lights). So it makes maneuvering at night a breeze and just makes sure the sensors haven't missed anything.
It's also good as well in daylight to use the guide lines to line you up with a parking space so you are perfectly central, and I use the red horizontal bar closest to the car as my guide on how far back to reverse leaving a perfect amount of space behind me between the car and say a wall to be able able to stand behind the car and open the boot.
TBH, you can't have enough of these types of aids in my opinion as one low bollard not picked up by the sensors can ruin your bumper (and your day) !