I always favour sensors over cameras. A set of sensors mounted to the bumper provide a much better level of awareness when reversing a big van with a full-size bulkhead, with audible bleeps warning you of approaching objects. The shorter the bleeps the closer you’re to an object, like a tree or car.

Cameras, on the other hand, provide a narrow view of what's behind and usually have a couple of blind spots that make it easy to clip a small wall or hidden post when reversing. The lens of the camera is also prone to getting dirty, which means the rear-view is obstructed by grime and water in the winter months.

If I was going to spend money on an aftermarket upgrade, I'd choose a set of sensors every time.