I've been using what I found out yesterday is a UCR, but I rigged mine slightly differently. Basically what I have is a 25' piece of amsteel blue with two alpine butterflies about 9' apart to which the ends of my hammock are fastened. The stationary "constrictor" parts are what hang from the tree straps, and the ridgeline piece slips through them. I like having a single piece of rope for my ridgeline and suspension, and alpine butterflies can be untied with a bit of work, so adjusting the ridgeline isn't too difficult. Does anyone else do this? What are the advantages and disadvantages you see with this system compared to the typical UCR setup or whoopie slings?