I recently saw "A Brief Primer on Hammock Suspension, Part II cord" video by grizz. One that really caught my eye was the "double marlin spike hitch" method. Basically you loop your cord around a MSH. You adjust the sag, then tie another MSH using both pieces of cord.
What intrigued me about this setup is several things:
It's stupid easy (Almost as easy as adjusting a whoopie sling)
easy to replace if it wears out (buy a large spool of cordage and replace if it wears out)
Can get closer to the tree than a whoopie sling.
I just tried this method on my porch using amsteel and seemed to work fine.
Can you use lighter weight cord? will the knot deteriorate the strength too much? does anyone else use this method?