I've purchased the silver whoopie slings and now the green. I can tell a big difference between the two. First, the diameter of the green sling is much thinner. Two, I find the tightening and loosening of the green sling is much more difficult. And three, the green slings seemed to have stretched during the first use where the silver slings were more firm and stayed in place. Waking up a good two feet below the rainfly felt weird. It's a Good thing that it didn't rain that night!