Very good points Topless. One way (in my opinion, non expert) to think about it is "What is the car doing that I don't want", or "what do I need more or less of" in the scope of sway bars. For my case, after going to stiffer springs/coilovers, I needed/wanted some adjustability in the rear to give more options in resolving an oversteer problem (that turned out to be caused by too much rake). I chose the center position of the eibach rear sway bar and it rocked. I also adjusted ride height at the same time so who.knows which it was
buy I am.liking this stiffer bar in conjunction with my current setup