So what does valving do (one way or the other) for the ride? Make it smoother/stiffer? If that's the case, I'd be interested in revalving my front shocks to soften the ride a little.
Yes - valving, in addition to spring rate, control how the truck rides, and how controlable it is, and how it handles on curves, bumps, etc. It controls how fast or slow the suspension reacts and returns to a neutral state after any action placed on it. Think of it as brakes for yous suspension, it's stopping the movement, both up and down. The stiffer the valving, the harder the shocks "step on the brake" and stop or slow the movement up and down of the suspension. Usualy it's diffrent brake rates for up or down, and depends on the spring and what type of ride and driving you do.
Softer springs, less valving = softer ride, less control.
Stiffer springs and more valving = stiffer ride, more control.