It's not a one thing you add and go "wow! what a difference!" type of deal. It's a part of a system of upgrades that, as a whole, make for a better handling car. If the LCA reinforcement was all you did, you wouldn't notice it. But as you add bigger torsion bars, better brakes, better tires, etc, you put more force on the suspension, so upgrading the LCA's makes sense. As does reinforcing the K member, adding frame connectors, etc.
