The big advantage that I can see in these systems is more precise adjustment of the spring rate. The front suspension seems to be a toss up. Gain rack and pinion steering, gain unsprung weight (not good) from using a coil-over unit. On the factory suspension, the torsion bar is completely sprung weight. The other draw back I can see is that this system moves weight farther forward (not good).
The rear suspensions seem to be better deal. While leaf springs have been holding up vehicles since the 1700s, things have needed to happen to adapt them to ever increasing horsepower going through the axles they support.
Personally, I'm not a big fan of the Panhard rod used for lateral location of the axle. The one on the Control Freak system is way too short. Here's the deal. The Panhard rod places unbalanced unsprung weight on the rear axle. Furthermore, as the rear axle descends through its travel, the rod binds up (the driver's side in this case) limiting how far and how freely it will descend. The other side of the axle is un-encumbered. In an extremely sharp, fast turn it is possible for the center of gravity to cause the Panhard rod to act as a lever. This could cause the car to "pole vault" in the best traditions of the VW Beetle, M151, and pre-65 Corvair. A much better solution would be a centrally located Watts link.