I recently purchased an UL Travel Hammock. I find the lines that come with it are kinda short, so, I made new suspension lines using 4mm (same size) rope, and made them a little over a foot longer than the original. I also added a couple more knots for more tree diameter/ distance options. It worked out to add only around 1.5 to the whole set up.
I like the simplicity of this suspension system! Sure makes for a FAST set up!
Once I get the ropes tightened up around the trees, there is NO movement against the tree bark, which was a pleasant surprise. I've only used tree huggers in the past, and I find with the TH system, the way the ropes are wrapped around the trees seemed to actually do less damage than my tree huggers! They just don't move once they are up and tightened.