Within each category there are various methods of positioning components that effect the weight capacity and handling characteristics. This FAQ will describe the basic differences between these suspensions.
Most school buses use leaf spring suspensions.
Most light and medium duty trucks use spring suspensions. After you read this article, you will understand why this is true. Handling on the highway is significantly affected by crosswinds or the wind forces created when an 18 wheeler blows by the motorhome. The close mechanical coupling between the axles and the frame of the motorhome transmits noise, vibration, and side forces. Except for small rubber or plastic bushings, there is a steel to steel connection.