I recently ordered and received the 12'x11' silnylon Hennessy hex tarp. The tarp is touted as being 19oz, and since I don't have any scales I'd have to go with that number. This is a large tarp, but extremely light for its size.
The tarp arrived in a generic envelope, with only the tarp and my order form inside. No external packaging or shrink-wrap, or any marketing of any kind. Pretty refreshing, imo.
The tarp is made similar to the polyurethane coated tarp that Hennessy sells -- it has little pockets sewn into the corners for the tarp line to go in when not in use. There are round plastic ring tie-outs, as well as little mitten-hook clips on the corners as on other Hennessy tarps. The color is a nice "Coyote Brown" (a selling point for me) and blends well with the surroundings, it doesn't stand out.
The sides are not cat cut, but it the tarp still pitches fairly taut, and though it rained all night, there wasn't any stretching or drooping of the tarp material. My concern about the small guage line that is provided proved unfounded. The line did not stretch either, even though it got wet. There wasn't any "tarp flap", even in the strongest gusts. In heavy rain, there were no leaks or "misting" through.
I got a chance to test the tarp Saturday night (took no pictures though, camera is not waterproof). The weather was windy, raining, slightly cold (33°F down to 26°F). I set up the tarp in the wind, before the rain came, with no problems, then went out later and set up the hammock in the rain. Never got wet, except for the few minutes I was out from under putting up the suspension for the hammock. I did take down the tarp for the biggest winds that arrived the next day, winds gusting up to 40mph that knocked down some large limbs nearby in my neighbor's yard. Didn't want to risk messing up the tarp for the sake of a test. I'll let somebody else do that test.
I would highly recommend this tarp for the weight and coverage. I think it's well worth the expense to get this kind of coverage to weight ratio.
Warning: For those trying to avoid buying things made in other countries (and good luck to you), you may want to look elsewhere. There's a tag on the tarp saying "Made in China".
Hope this helps...