Running GC/Koni Yellows custom spring rate 350F/450R with a 22mm sway bar. I autocross and daily drive my car. It is a very comfortable ride and the only suspension noise I get is the squeaking from my toasted rear trailing arm bushings.

What I like about GC/Koni Yellows:
+Full rebound and ride height adjustability
+Custom rates
+Easy assembly
+Solid construction
+Performance to price ratio is very high
+They look cool
+Easy installation

What I don't like about the GC/Koni Yellows:
-Spring not preloaded until car is on the ground
-OTS Koni Yellows can't handle spring rates higher than 500 lb/in. SPSS revalved Koni Yellows are required.
-If you want to slam the car, you need the GC tophats