The Panther's doing the Panther *rawrs*
Alright, this is me after trying the E640 springs, those panthers are made for 66Kg, so those aren't made for me, but it's astounding that I couldn't push them through with jumping. They were really pretty soft even in comparison to my own springs, the further you push them the harder they get, so you could say Soft on the outside, hard on the inside, who doesn't want that ;)

Photo (C) Syah