The bolt on tubing allows for cleats to be replaceable compared to bonded cleats. They also are more heavy duty.
The chain drive prevents extreme forces from being put on the belt, as well as create a more economical goose neck conveyor belt. A standard rubber goose neck conveyor would be much more expensive as the belting needs stiffeners, whereas the combo belt uses the tubing and reinforcing tabs.
This belt is the step between a solid PVC or rubber belt and the Metal Hinge Pan. A Metal Hinge Pan being the most heavy duty and costly.