I've shot 3D for years. For me it's a wonderful way to prepare for the upcoming bow season or out of state trip. We seldom shoot standing straight up and all nice like the posters. We shoot off our knees, our bellies, from behind brush, sitting down, and as many other hunting scenarios as we can come up with and still shoot a given course safely. Another thing we seldom pay attention to is the distance markers, which are real scarace in the woods! Back when I was single, sort of between, I used to leave my house at 6:00 am on Sunday mornings and drive a 'circuit' once a month to make three 3D shoots in a day. I was never interested in plastic trophies just improving my shooting skills.
Best of luck, Arch