I enjoy using a poncho-tarp. It makes great rainwear, covers my pack, and is dual use as a tarp. However, I have been slightly dissatisfied with my rectangular 5'x9' poncho-tarp for a few reasons.
First gripe: 5'x9' is a tad small for full coverage in most tarp-mode configurations. This results in me carrying a relatively heavy eVENT bivy in order to get full protection. I would like to move to a PQ or Momentum bivy with a fuller coverage tarp.
Second gripe: my current poncho-tarp has a round attachment hole for the hood, which is hard to close and hard to tension across. I would like to go to a slit attachment for the hood that I can roll to close.
Third gripe: the 5' width ends just below my elbows when in poncho mode, leaving the lower end of my sleeves exposed.
To solve these minor annoyances, I have been sketching up new patterns, with the hope of building one soon. Take a look and see what you think. Any major drawbacks that I am missing? The wide end would be folded under when used in poncho mode. I would be able to use stake loops midway up the sides as thumb loops. And the hood would have ties for when rolled up in tarp-mode.