The Grand Trunk UL is wider than the Nano 7 too-- you lay on the diagonal, so width is important. IIRC, the fabric alone for the GTUL is 9oz and it works fine with Amsteel whoopie slings in the end channels for suspension. You can use large carabiners in the end channels a la Nano 7, but it just adds weight. For those who sew, whipping up a light hammock from 1.1oz ripstop nylon is a 30 minute operation.
The poncho tarp is a very interesting design. I never would have guessed it would be that long. I take it that you have to tuck some material under and secure it, like the Gatewood Cape?
The Hennessy Cape is a 69"x 110" parallelogram and 137"x 120" on the diagonal, weighing 11.8oz. It is pitched asymmetrically, so it doesn't have the nice end protection that a squared-off tarp with doors would offer.