The big difference i have noticed, The extra thickness. The attachment to the rail save is fused on instead of a knot. When u det dumped on small to med waves, the leggy feels likes it doesn't stretch half as much as normal leggys,
They claim the leggy can stretch to 3 times its original length,, on head high stuff it's hardly getting worked at all. yet to try in a BIG swell.
It feels really solid and secure , a lot of times on the old leggys i was thinking 'yep, this is going to snap then it doesn't and the board is flying to my noggin at a 100k.p.h. Or it does snap and is heading for some rocks.
should be safer for other surfers paddling out if it does't stretch as much.
they are pricey at $50, but i think that extra few dollars is a good insurance.