Thanks for the information. Check out this key section of it,
"... The fact that torsion bars are a linear spring effect the ride quality in a negative manner. Luckily, with modern technology and the advanced design of independent front suspension (IFS) ride is still going to be far superior to that of a progressive leaf spring and a solid front axle. Also, you may notice that the LCA on the GM IFS seems to be resting on its upper bump stop. This is not only a bump stop, but what is called a progressive dampner. It compresses at a progressive rate, simulating a progressive rate spring, and letting the torsion bars achieve close to a progressive feel. Another con is as you increase the ride height by adjusting your keys, the ride gets worse. Now it’s a common misconception that there is more of a load on the bar and this is the cause. That is impossible since the LCA moves as well, so there is no more torsion on the bar than before, the spring rate does not actually change like many belive. The twisting action does not change the pre-load on the bar directly, so cranking your bars is just like adding a block in the rear or a coil spacer. It is simply changing the position of the spring. Just to clear things up, pre-load is the amount by which the torsion bar can't return to its original (unloaded) position due to be installed in the truck. The reason for the bad ride quality is instead a combination of things. First of all, when you adjust the height up, the angle between your LCA and the ground is increased which effectively does reduce your pre-load by reducing the leverage your LCAs have on your torsion bars. This negativly effects the ride by taking the torsion bars out of the preload range they were designed to work in. In combination with that, if you crank too far your UCAs have very little room left between them and the lower bump stops, reducing downward travel. You also pull the LCA away from the progressive dampner, making it ineffective and putting yourself back into the position of having a linear spring. These are the reasons the ride gets worse! One last disadvantage is that like all other springs, torsion bars will wear out over time causing your front end to sag. The more weight on the front of your vehicle, the faster they will wear. Also, the more your suspension travels the faster they wear...."
What I see is that we are all altering our ride height, which is hurting the ride. Like in that article, the bump stop may be what makes the ride quality change as the truck moves through a bump etc.
The answer seems to be that a progressive rate is most desirable, and that is easier to accomplish with coil springs. The initial compression of progressive rate springs is softer than the rest of the motion. That makes the normal ride better, small bumps become less noticed. That's what I'm after,
