DROP: I re-measured how much the car was lowered after a week and it did settle slightly. New drop is Front 1 5/16" and Rear 1 3/16".
HANDLING: I was able to do part of a track day with the springs. I would say that the body roll has been reduced pretty significantly. I can't truly say that the handling made a significant improvement.
DRIVEABILITY: I was worried that I would ruin the ride of my Mustang by adding lowering springs. I really liked the OEM ride a lot and had absolutely NO complaints, so this was a big leap of faith. Adding the ROUSH springs (which were designed to go specifically with the OEM shocks and struts), has not degraded the ride noticeably. I would say it's slightly firmer, but in no way is it harsh.
I am very happy with the purchase and would highly recommend it to a person who is looking to reduce the wheel gap, limit body roll and maintain daily driveability!
2013 Ford Mustang V6 with Performance Package, Recaro Cloth Seats, 19" Brembo GT Track Pack Wheels and GT Premium 19" Wheels, OEM 3:31 gears, Airaid CAI and Roush Upper and Lower Grille.