Fantastic! I'm definitely in for one, regardless of the use of plastic or metal. I've just had some experience with the plastic buckles getting broken if a high-lift or tool kit gets slid or thrown on top of 'em. The metal cam buckles (Kayak tie downs) are much more sturdy for the long run from my experience. If the ends get frayed you can always cut a little off and re-seal the end with a match by slightly melting the end.
Personally, I think the idea is a fantastic one for my uses, as I already have the heavy stuff securely strapped down, and just need to keep backpacks and other relatively light gear from launching itself into the back seat!
I'm excited about the purchase!
-H-