My GT Premium has the factory "track package". Handling was exceptional for track days, autocross, but the ride was "way too rough" for family activities. The Koni "ADJUSTABLE" made a HUGE difference! I now have a GT Premium "Luxury Sport Coupe". Excellent ride on soft settings and with the simple turn of the easily accessible knobs, you can dial up for any spirited driving event! AWESOME! I highly recommend Koni "yellow" - BEST investment I've made for my car, I used the stock springs, but should also work well with lowering springs. You will be pleased!
KONI STR.T Review
AutoAnything shipped very fast and everything was complete. Did the install myself; bit of a pain but not bad so long as you can dedicate some time to it. The Koni STR.T kit with H&R springs handle noticeably better over stock, but not an uncomfortable ride. Would recommend these if you don't need to make adjustments, or the Koni yellows if you want the adjustable feature.