I watched Prof Grizz's videos this morning and then went out and built a new suspension system using a Marlin Spike and Garda Hitch (copying his setup about 7 minutes in on the video). It's a great setup and looks like it will be much faster to work with than the traditional Hennessey knot.
I was testing it out in my back yard and broke the line on my Hennessey Hammock. I have a ~8 year old Ultralight Asym and the exterior casing broke in the middle of the Garda Hitch (kind of like the two SMC rings cut it open), exposing the spectra core. The cord is feeling kind of stiff and I wouldn't be too surprised if 8 years of use has made the casing brittle.
Are there good instructions on replacing the hang line on my Hennessey Hammock? Any recommendations on easy to find (REI or Seattle-area climbing stores) cord to use? For a garda hitch would a slightly thicker cord be a better idea? On my ENO hammock I'm using BlueWater 4mm cord (900lb test, $7.50 for 30ft at REI) and I'm wondering if that is a good one to go with.