PST did a good job of explaining it, I'll see if I can add anything. The purpose of a shock is to dampen the rebound of the spring. Without a shock, a spring would react in what looks like a sine wave, compress-extend-compress-extend etc, with the amplitude slowly decreasing. The bouncy/floating feeling you get when your shocks are toast- you hit a bump, and ride the wave for awhile afterward. So, that would be underdamped, and the "softer" your shocks are the more underdamped the suspension typically is. Overdamped means that the shock is actually keeping the suspension from traveling it's full available distance, ie, you hit a bump, and before the suspension can fully absorb it the shock limits the suspension travel. That's what happens when a shock is too stiff. The "perfect" response is critically damped, meaning, the shock allows the suspension to fully absorb the impact and travel its full distance according to the size of the impact, but then controls the suspension oscillation so that it just immediately returns to its normal position. Obviously, if you change the spring rate the shocks dampening rate also has to change. With most shocks that's controlled with valving. You have a reservoir of fluid or gas, and the amount it resists change (the amount it dampens the impact) is controlled by the valves the fluid has to travel through when the shock is compressed or extended. A simple shock has no valving, so, it has a single dampening rate based on the fluid or gas pressure and the type of fluid or gas in the reservoir itself. Then it gets complicated. Better shocks have more valves, so their dampening rate actually changes depending on the speed of the impact/load. So, small bump=small dampening rate while big bump=big big dampening rate. So, they control the suspension better. The more valving, the wider the range of dampening. KYB's are cheap(er) shocks with little valving. They have a small dampening range, and are set up stiff. That means the work better on larger bars than stock shocks, but with small loads, like driving on a typical street, their dampening is too stiff and the ride suffers because you're in the overdamped mode where the shocks are limiting what your suspension can do. Bilsteins have more valving, so, you can run larger bars and the shocks keep the around town ride more bearable, while still controlling the big hits. The Hotchkis shocks have more valving still, allowing them an even wider range of dampening, allowing them to adjust better to around town driving while still being able to handle really large wheel rates/torsion bars. As I've mention quite a few times, I've run both Bilsteins and the Hotchkis Fox shocks on my Duster with 1.12" torsion bars. The Bilsteins were better than any other shock I've used with that large of a torsion bar, they do a good job. But the Hotchkis Fox shocks (mine are non-adjustable) do an even better job at the extremes. Meaning, they're a little softer around town with the small loads/impacts, but do an even better job of handling the big bars when things really get interesting. I think with a slightly smaller bar, like the 1.03's or Firm Feels 1.06's, the difference between the Bilsteins and the Hotchkis shocks would be less noticeable. But as the bars get larger, the Hotchkis shocks make more of a difference. As far as KYB's, I wouldn't run them on anything again.