I've rubbed the straps of my alien shade down trees with no ill feelings or even a damaged thread. I picked up a 20 pack of 8" tarp straps for $5 and it's been cheap insurance incase they come apart but at this point the Alienshade is as durable as the Honda top and a whole lot nicer to ride with.
Agreed. I haven't had mine on long enough that I want to start speaking to the durability too much but you can get a pack of like 25 bungees for 7 or so bucks on Amazon. I'm more concerned about losing them when transporting than I am breaking at this point.