Well this IS Backpacking Light and the things are very light, fast and adjustable. Sgt Rock has a pretty near full hammock system at @ 1 lb using among other devices "whoopie slings" Makes "hanging" competitive so to speak with "ground dwelling" from a weight stand-point. What's to complain about less weight, less volume, and greater ease and simplicity?
Relatively easy and fun to make as well
And DEEP in the tradition of rope lore and knot tying. Besides which one driving force behind the application or transference of this particular bit of rope lore with time-honored, traditional sea-faring origins is the fantastically easy loosening of the /connection/knot after a night of lots of weight and pressure that can pull a typical knot so tight you need 2 pair of needle-nose pliers to pull it apart; and in some cases the rope can literally melt together.
Hopefully some more knowledgeable hangers can add to this......... I'm unfortunately still a ground dweller but one with great respect for all things nautical and the art and science of "hanging".
There's lots of interesting ultra-light hammock gear at this site: http://www.outdoortrailgear.com/ ............. including slings