Had the ground control kit installed yesterday at Group 2 Motorsports which is a fantastic shop. I opted for the 440 lb/in front and 600 lb/in rear springs. Watched the entire installation. I have only driven it for about 30 minutes but I'm very pleased. This, in my opinion, is a better daily driver than the H&R springs I replaced. It is firmer but in no way is it uncomfortable or jarring. And there is significant decrease in body roll and this car really feels planted now. I kept the ride height essentially the same as I had with the H&R springs. This setup will go really low if that is what you want but I see no advantage to that. So far I am very pleased and can't wait until next week when I get to try it out at Pacific Raceways with the Alfa club.
2015 f80 M3, 2010 GR3RS