When adjusted properly, the lever to raise, and lower the 3pt hitch is spriing loaded. It's my guess that if you move it in the direction required from the neutral position to the stop, and release it, the lever will return to the neutral position, limiting the movement at the rockshaft to about a quarter inch. It would depend on how far to the rear of the 3pt arms the implement is how much that would move. The system looks like it would work OK when using the ground level as a reference. One could lower the implement slowly until it touches the ground, and then bring it back up a certain number of "hit, and release" movements to be roughly in the same place each time. I also think it works pretty well if you are making small adjustments as you move along grading, etc. PC, on the other hand is great for returning to the same depth either above ground, or below ground every time with out requiring a reference to the ground level each time by setting the depth stop, or just retuning to the same number on the scale each time. If one is moving along wavy ground, and trying to level it by compensating the depth of the implement to the tractor movements, I expect that either works just as well. I really think that both sides are right in certain situations in this debate. QI= ground level, or eyeball for reference, PC= reference scale.
