Agreed... Better safe than sitting on the ground with a sore backside! My stock Claytor strap that I use with ring buckles are more spongy? than the webbing I bought for my wife's hammock. Mine seems to get a better bite, and her's did slip the first time she set it up, but I don't think she lined it up, and we did put a safety behind it that time since she was just starting out and didn't trust it anyway. It would seem that the thinner, slicker straps would be more prone to slipping, but after dressing them properly, they have not slipped.
Anyway, back to the tarps.... I'm very interested in this one!