I've had both the "R" springs slammed my ride and the ride quality is not all that great, very bouncy. My front tire is literally in the fender. My car hits the bump-stops on the slightest of bumps (adjusting the shocks/struts to compensate). I have to drive up my driveway at an angle to not scrape the exhaust, but damn the ride looks good with the "R" springs. The "Q" springs only lowered it about a 1/4" but they rode very well. I haven't been back to the track with the "R" springs but I will compare times as soon as I get my rear gear situation straightened out.