>I'm going to hang my hammock with cape and try it.
I tried the Gatewood Cape in several orientations above a Hennessy Hammock Explorer (about a foot longer than the Backpacker models). I want a taut pitch because it's likely to be windy, and I don't sleep well with a tarp flapping all over the top of my hammock.
With the vestibule at one end of the hammock and the back at the other, the cape was too short to cover the hammock completely. The cape measures about 7 feet from vestibule to back, and it covers even less when the hood is pulled up. Bummer, because this would be the easiest pitch. (It might work on a Byer of Maine Moskito Traveller hammock because that has a truncated hammock body.)
I pitched the cape over the hammock with the two side guys on either side of the hammock ridgeline. Unlike the Silshelter in the previously posted picture, the edges of the cape are supposed to be pitched flat. If you hang the sides of the cape below the hammock's ridgeline it distorts the pitch; if you suspend it entirely above the hammock it won't protect from wind-driven rain, and it jumps like crazy in the wind.
I pitched the cape asymmetrically, with a front-side guy on one end of the hammock and a back-side guy on the other, and it didn't make a taut pitch. The back and vestibule don't stretch out nicely.
I found the best fit was to hook the 6" front-side guylines to the hammock's tarp hooks. (The normal tarp hook position is just about right, so it doesn't interfere with the Hennessy SuperShelter under-pad/under-cover system.) I could then guy out the back and back-side guys in a taut pitch. Unfortunately, doing so makes it almost impossible to stake out the vestibule nicely--when you stake it taut, it doesn't pull out the vestibule.
I tried running a ridgeline through the cape's side pull-out guys and the hood. If you just tie the ridgeline at the level of the 'tree-huggers', the cape lays on the hammock's mesh top. If you have convenient branches and can tie the ridgeline 3-4 feet higher it will work if it isn't windy; it gives sufficient clearance above the hammock and the rain can run off.
In order to complete a taut pitch, I had to pull the hood cord tight and tie it up to a convenient, higher 'branch'. If you don't have a handy branch, tough luck. In order to complete a taut pitch of the vestibule, I had to unzip it and guy out the two sides. Doing so left a triangle where rain could come in, but it wouldn't be a problem if the back was pitched into the wind.
Guying the side pull-outs up to a branch or branches definitely improves the pitch. If they aren't, a good breeze will push the cape against the hammock.
Now that I've written a thousand words, here are two pictures, taken with the hood guyed lower and the vestibule closed. Good coverage on the back side, fair coverage on the vestibule side. Sorry about the dark pix; I have better but the hood was guyed higher and the vestibule unzipped, which probably isn't how it would be used in the rain.