I went with eibach because of the ride height. I didn't want the car to sit too low. To me, in the pictures, the rear looks a lot lower with the granetelli springs. I'm happy with my decision.
2016 SS,M6,Spare,Roof,Rohana RFX5 Wheels, Kooks Headers, Hi flo cats, Rotofab, Heartbeat, Eibach Springs