As Poncho, I love it since when it's too hot yet raining...
I can just roll up the front & attach the back part to the front's first top button to get the back secured & not flapping on my legs. In that mode, it acts like pack cover
I could roll it up all way over to back of my neck & insert it in my pack's loop to hold it in a place when it's too hot to put it as "normal mode" or the mode that I've mentioned first. It might be little bit confusing as in the writing but once you have the poncho/tarp... you probably will have the same idea or better idea than me.
As Tarp Tent, I still have to experiment with it but I do use it with another tarp covering the ground then I'm all set...
You will just need to have a stakes & ropes to hold them in place. I would recommend you to experiment with it beforehand & have few various methods since sometime one method isn't best in certain scenario.
Overall, I'll say it rocks!!! Especially when it saves me a weight of tent & rain gear (jacket, pant, pack cover). I love it as ultralight hiker!