Even a slight lift beyond stock will result in more lateral motion in the axle, resulting in problematic handling, steering feel, sway and potentially wobble at higher speeds.
This panhard bar kit restricts the lateral movement of your axle, yielding vast steering improvements (especially at higher speeds). Customers rave about their improved "race car" handling after installation.
If you have a spring over axle setup on your Samurai and you're not yet convinced that a Panhard bar would benefit you, try this: Take a buddy with you and park your Samurai against a curb. Get out while your buddy takes the drivers' seat. While your buddy turns the steering left and right so that the tire is pressing against the curb, watch how much play there is between the body and the axle. If the lateral movement you see in't the result of worn bearings or bushings, a Panhard Bar would essentially eliminate that movement and deliver significant improvements in handling.