I have the Paratarp and I have used it as a shelter during the day, rather than for an overnight shelter.
While it can be rigged tight to the ground, I have had better luck using longer poles and leaving around a foot or more of gap to the ground, with cords through the peg loops.
In the Olympics, if I didn't rig some kind of shelter for my "stand", I found out I got wet through and it made it hard to stay out all day. With a shelter, I could make coffee on a small gas stove, glass for deer, etc. and stay warm and dry. (Well, drier. Still got a little wet from the hike in.)
After sealing the seams, it is raintight and incredibly light. If I manage to tear this one up, I will probably get another.