TRACKBAR, anyone here run one?

I understand why you would see this on a coil over type rear suspension, and yes there is an amount of side movement within the leaf spring suspension. So the point is, after upgrading the springs from stock, how much would a panhard bar really help the hard cornering, or yaw of the car?
Please understand that there is more benefit in the panhard rod/track bar than just getting rid of spring twist and lateral dislocation of the body; those benefits alone are more than you realize if you ever really drive cars with and without track bars (or any good lateral location) enough.

The other very real benefit is in tuning for oversteer and understeer, which, if you care about handling (aren't you the guy who wants to beat the 'vettes?), is another important tool in your tool chest of chassis tuning. There is a very real reason that the modern NASCAR cars all have adjustable track bars, and that is it! You get this with or without leaf springs, coils, etc. If waht you have a is good enough, then don't bother. But if you are serious aobut beating those 'vettes.......