Reason I prefer the track bar is that it moves at the same rate and in the same arc of travel as the lower bars... Things do move around down there a lot when you drop the hammer with some sticky tires or slicks. As 31 mentioned, the track bar forms 2 triangles which are the strongest support of any geometric shape, and whatever deflection there is in the ends or the tubes themselves (yes, they do deflect under load) the movement is in the same direction of travel and arc on the lower bars and track bar with all the torque being applied to the forward mount points of the lower bars. A panhard bar actually transfers torque to the frame rail where the end is mounted. Probably more of an issue with us gear bangers then with the automatics, and not really an issue on the street cuz if you have enough horsepower to make deflection an issue on the street it will just blow the back tires off anyway......