It's the elasticity that makes them better. I can't use them under the shell like it says to in the directions - I started to get bruises on my shins within hours. For some reason when under the shell, they made the boot tongue twist sideways and dig in. But on top, like in the position of a regular power strap - they're fantastic. Easier to get them fastened to the right tightness than velcro power straps too.