mated to just about any spring set-up, but very agressive/much lowered springs may have too little travel for the Koni's (unless they make an adjustable"short"shock for the front, they have a website). At minimum, they are comprible to a Boge touring shock but can be adjusted while on the car to sport Bilstien hardness. Koni is a great shock and is even more appealing due to the adjustability that also offers the ability to "re-tune" when they get high mileage and begin to soften up, just turn a degree firmer. As for springs making a ride harsher, they really won't, its the shock/strut insert that really affects the harshness, the firmer springs will greatly control the car better especially at high speeds and can seriously save your life when you swerve to avoid a dead deer at 85mph!(pers.exp.)