I just posted in another topic about this.
Originally Posted by ///M Power
Your car already has sway bars. They really aren't that thin. No, they are not worth it as your first suspension modification. You should save up for springs/shocks or coilovers if you really want to feel a difference. I added aftermarket sway bars after my shocks and springs and barely noticed a difference, but rather lowering the car with stiffer shocks helped far more than anything i've ever added. A strut tower brace is not worth it as a first modification aswell. Beware that stifferening up the body too much can actually hurt your performance. Also, the only truly effective strut tower brace is one that is welded to the strut towers.
Save your money.