I have a set of Teraflex composite leafs waiting to go in a project Jeep that I keep getting stalled out on.......I bought them used and the previous owner used them on a "rock crawler" said he loved them! I think that the idea of the kit fell to the wayside due to the high price and fear mongering that the leafs would not hold up. Everyone I have ever talked to that actually ran them and had actual real life experiance with them really liked them and said they held up great!
Tera-Flex is local to me and I talked with a former employee that helped prototype them........they are composite leafs off the back of an Chevy Astro van with a custom ends on them that use the same joints as their control arms. After looking at the Teraflex leafs I have and Astro leafs in the junkyard I can say without a doubt they are the same, only the Teraflex leafs are coated in a bedliner type materal to give them abrasion resistance.
Looking at Astro vans in salvage yards I can say that maybe 10% of them have splintered leafs in the back......most of those with splintered leafs have had aftermarket tow hitches (i dont think composite leafs were meant to be used for towing) or have been rear ended.
Tera Leafs:
Chevy Astro Leafs:
(not a great photo but compare the "dog bone" shape as well as the typical splintering)
Volvo 960's also have composite leafs:
Corvettes use composite leafs:
Circle track racers swap them in:
They also make conversions kits to swap composite springs into:
-classic mustangs
-Camaro, Firebird and Nova
-53 to 82 Corvette
-62 to 67 Chevy II
-55 to 57 Chevy Car
I think they are more common than most people realize............