I have a set on ConVerTT now and a set that is on Project SlickTTop. I haven't had the slicktop Out enough to offer a strong opinion, but on the convertible is was night and day when I switched from KYB/AGX Eibach to Powertrix. Switching from the heavy Moda R6 wheels to the suoer light LMGT4s also made a huge difference BTW - just another variable to consider along with spring rate.