I can compare two different suspensions to conventional, both on a 15,500 GVWR fifth wheel . One was the older MorRyde LRE , as long as the shear springs stay in good shape they tow pretty good. The other is the recently bought fifth wheel with the Comfort Ride, with shocks . Not sure how much better a 15,500 GVWR fifth wheel could tow, its pretty impressive.
Only way one could really know would be to tow the same trailer with the different suspensions, with the SAME truck. They all are going to be different.
IMO the Comfort Ride ,with shocks are as about good as you can get , and I will say short of IS , I say that only because of the obvious increase in price of all the others, I would hope the cost the benefit is there . Me personally I see no need for IS . I am thinking IS probably shines more with the heavy heavy fifth wheels .
