hey guys, have you checked out the fig. nine thread or the ring buckle thread lately? i figured out you could use the fig nine as a quickly adjustable suspension for rope. my setup is just like described above, with the nine attached to the webbing instead of rings to webbing. i like it because of the use of much lighter line replacing just over half the webbing, which makes quite a weight savings, and line is much less bulky as well.
it seems your setup may be as fast as the webbing/rings, but with less weight.
with mine, you have to wrap the fig nine, which takes just a second longer, i was however able to reduce the weight of 2 fig. nines to 1.25 oz.(with a hacksaw and file), which is 3/4 oz lighter than your required 4 rings. which isn't really all that much weight. i think 2 un-cut nines would be just a few grams heavier than 4 rings. either way, its the exact same setup just with different hardware. i wonder if everyone will be switching back to straps and line now?
slowhike is right about not forgetting your straps on the tree though, been there done that.