five.fifteen plus wrote a review of Sea To Summit Ultra-Sil Stuff Sack on March 24, 2014
They are light, strong, keeps your stuff dry and organized.
I have so many to hold clothes, wet jackets, climbing gear, slack lines... you get the idea.
For a size reference: the small holds 80 feet of 1" webbing, two 10 foot sections of 1" webbing, 4 carabiners and 2 rap rings. And there's still a little room to spare.
A little more expensive than others but worth it in my opinion. I only wish we could choose the color.