Poncho and capes aren't the trim fashion statement, that's for sure. Going on previous threads where people write about not taking rain gear, I think the Gatewood makes a very good alternative. It's a tarp tent and will keep you and your pack nice and dry if it does pour. The Cape has more loose fabric tucked under than a poncho does, but it is easy to manage and makes for a much better shelter. If you don't need rain gear, you didn't pack one more gram than needed.
Ponchos are light and relatively cheap, but they don't give full coverage as a shelter. I think a poncho tarp needs a bivy to be a complete meal, which steals part of the the bargain for weight and cost.
I usually carry a poncho and a space blanket bivy for my day hiking CYA setup. I've sat out some heavy rain showers under a tree sitting on my Z-seat, wearing a poncho and my pack between my legs. Everything stays nice and dry and I'm still covered to the knees when I'm on the move. The space blanket bivy is for worst-case-stuck-out-overnight scenarios. That combo is 2/3 of what an average rain jacket weighs.
All you need for a poncho or cape is what I call a "monk's belt." Take 8' of light line and double it with a toggle. That goes around your waist and under your pack, with the toggle tucked above your waist belt buckle so it doesn't slide down. The loop simple hooks around the toggle and can be adjusted easily. That tucks in the sides of the poncho and wraps it up under your pack and keeping it away from your heels. You still have good airflow out the sides and the poncho is tamed in wind and brush. You will look like a tossed salad, but I hike solo, so there's no one to see me, not that I care anyway.
That bit of line can be used for emergency repairs, a snare, a spare guyline, a fire bow, or a shoelace. 0.25oz/7.1g total. You can use light shock cord the same way.

