I've been running the FlexAForm mono fiberglass leafs since the lat 1980s (~1988-9)... never a problem on mine.. never seen aothers fail, etc. these are made by the same company that makes Corvette OE leafs (Flexaform)... they worked with me for the best choice. They do take ~2-weeks or a bit more to initially settle at their flatness (so, I loaded the car down with weight for a cpl weeks as it sat in the garage). they react faster than metal springs (my previous were de-arched hemi springs from a Challenger). They'll save you ~25 pounds per side. I used to trailer the car... sold the trailer ~7 years ago (and tow vehicle ~10 years ago)... began driving the car I've also loaded the car with travel stuff for long distance driving (typically to a race event)... basic tool box, lt wt sizzors jack, spare parts/fluids, tent/cot/sleeping bag/clothes, cooler... brings it down a little for the haul but I spread the load out front/rear... very driveable... no problems. You do want to have the poly bushings installed front/rear (may have to turn down the OD of the fronts bushings a little for installation)... and the bushings might squeek a little... what else is new. I'm aware of some serious national SCCA Solo autocross racers using these leafs... no problems I'm aware of. I've considered the Hotchkis (3-leafs?) IF I'd ever go back to steel, but they're a little too soft for my setup, so, I'd probably add leaf to them and have them de-arched as needed. Weight reduction is important.