Thanks! Shoulda thought of backpackgeartest.org myself. I'm lazily looking around for a product like this cape -- it'll be my dayhike just-in-case raingear/tarp, so it needs to be super light to fit into my dayhike pack. Seems like this and a few other entries might work.
My 11oz. tarp shelter is indeed the Six Moon Designs Gatewood Cape Shelter. If you really want to get into tarp shelters, check out the forums at
Backpackinglight.com. It's where all the fanatic gram counters hang out

Some of the guys there are going out with 5 pound (and less) base pack weights. A knife in that world is an SAK Classic or a Leatherman Micra. The hard core ultralighters would crap over something like my 7.5oz Entrek Javalina, let alone some big Swamp Rat or Busse chopper.
The basic ultralight tarp is a silicone coated nylon tarp, preferably with a caternary cut, so it piches taught and sheds wind. Most poncho shelters are so small that a bivy sack is needed to really make them work. Add Sprecta lines for guy lines and titanium stakes. Trekking poles or sticks are used for pitching.
From the tarp, it goes to shaped tarp tents and single wall tents. Many hover around 2 pounds. Henry Shires is a well known maker, as well as Six Moons Designs, and GoLite. There are more. The ultralight hiking world is full of mom-pop garage businesses and oddball inventors, so there are all kinds of options. There are compromises and most of the UL stuff isn't cheap.
The gain in the shelter I use is that I can leave a 12oz rain parka at home and get my shelter too. My previous shelter was a GoLite Hut1, which weighs 15oz, for a net weight reduction of one pound-- the 12oz rain parka plus the 4oz savings on the shelter.
For day hiking backup, one of the Adventure Medical bivies and a poncho will cover a lot of bases. Add some line and 10 light stakes. A space blanket will do for a ground cloth. Of course I think the Gatewood Cape is the way to go too.