When you use the rancho's every adjustment affects the extension and compression. So for the stiff setting on compression it is also stiff on the extension not allowing the car to lift in the back as easy and put weight on the back tires. The lose setting is the same fast sepration but no compression. The afco's you adjust each one seperate. On mine I have them lose as can be on the extension and firm on the compression. I do have the extension 2 setting firm on the drivers side to control roll over so the rear lifts equally. Spend the money on the shocks it is well worth it especially for small tire cars.