I looked at those but I think the ST has a poly/composite support just like my Gaernes G-RW.
The higher end Sidi's are metal or Carbon Fiber, but I don't know if the design is better or not.
Novice #728
Lucas Oil - Vesrah - BD Racing - Vortex Racing - Shorai Batteries - Sidi Boots - Josh Henke
Torquasaurus #98