also of mention, it's easier. making a gathered end hammock, and a cat cut sil tarp is much, much easier so far as planning, design, application and production goes than say, a solo tarptent. this applies also to some of the more simple but gracious shelters, like the Mid style and many tipi's we see in today's market.
I'll also add that you may consider 2 tarps. summer may not require a 10×12 and you can shave ounces from your tarp while adding it to your hammock (bugs, summer) but w/ a cuben tarp you pretty much negate this need, at a cost. so… how much would you value a summer sil tarp, and a winter sil tarp combined? are they near the cost of just one cuben tarp? if so, start saving. in the long run, a cuben tarp valued for such light weight may not "do it all" but its pretty darn close.
I own 4 tarps. a standard sil by MacCat, 2 of my own in sil, and a zpacks cuben. I have found over the last year, in all conditions, the cuben wins hands down. the ONLY drawback is that I have a sensitivity at times to a full moon's output. that's when pulling my BR beanie over the eyes takes care of the problem.
mike