Tein SS vs Tein Flex

[aaronng]

http://www.overl0ad.com/legacyfiles/Tein/Flex.pdf


the flex says the same: "full length etc etc..."

I see, it preloads it using the full length of the piston rod as in the pic in the bottom right. But does it give any benefit? When installed, the weight of the car compresses the spring anyway to a similar amount if it didn't have any preload.