i think if yours are fine. then your better off saving your cash on labour doing somethignelse - I only replaced mine because my ball joints snapped. and the cost of 1000$ or 275$ per control arm had me go with the cheaper toyota one.
I cant tell the difference to be honest. maybe its there, maybe its better suited to work with a few other supporting mods like coilovers -- ionno but its not something my buttdyno feels is making any difference in handling.