I think a lot of people are forgetting or dismissing contact pressure.
A tire with a smaller footprint has a higher contact pressure than one with a larger footprint.
Contract pressure directly affects handling and traction.
I do believe that the chains are an advantage in most soft terrain.
I am however skeptical that they'd be advantageous in the rocks. I see the tire spinning as the chain makes contact with a rock, then grabbing as the tire itself gets traction. Repeat this over and over.....Seems real herky jerky and a good way to break parts.
It's just one of those things I won't believe until I see.
Call me Thomas.
Allen