2nd thoughts...I've been using this UCR over the std. HH suspension rope (looks like spyderline?) which is a sheath/core type rope. It holds great, but lately I've started wondering about maybe I'm slowly moving the sheath over the core? I don't know how much length it takes for the sheath to transfer the the tension to the core, and how much load the sheath will take by itself. Could the sheath fail by itself dropping me? Hmm...
The grip is awesome though (no worries about slipping thru the UCR), and for the weight of only about 6' of amsteel blue I have complete adjustability, so I'm loathe to give it up. If anyone has tried this - UCR with amsteel and sheath/core rope for the main suspension line - and has a horror story, please let me know.