Used the 1680D Ballistic Nylon for the bottom of a duffle bag, (the rest was X33 Multicam), and this stuff feels sooo strong. Highly recommend this if you're looking for a heavy duty and heavy fabric that can take a beating.
Great stuff. Used it on the bottom straps for my dogs hunting vest. Perfect choice since she's always barreling off trail. I doubt many other fabrics would hold up to her abuse. Very durable and smooth (easy cleaning).