The number ONE reason for air-suspension is improved ride at better speeds, and improved safety and stability.
The problem with coil suspension and electric drum brakes (leaf suspension is far worse and is not even worth discussing) is:
Watch This Video Before You Read Any Further!
Discover how air suspension really works for offroad caravans and camper trailers. Using a simple model, Bruce Loxton unravels the mystery surrounding the suspension needs for offroad travel with single & dual axle trailers and caravans.
The number TWO reason is you use just one finger to level your off-road caravan at the campsite.
Download a 28 page guide on off road caravan suspension design with focus on coil springs and air springs with ride height control.
To see how the Air Suspension System works here is a video of it in the Kimberley Kruiser lightweight off-road caravan: