Good point Bobco,
If I didn't know where the vitals were I wouldn't know where to shoot. I guess we take that for granted. But a 3-d target is great once you know where the vitals are. It gives a real feel to target shooting and you can see what works and what dosen't. I almost never take a quartering toward shot at a deer. The % aren't in your favor on a shot like that. But take that logic and shoot it at a 3-d and see what really happens and how small the margin of error really is.
My 3-d has the vitals marked no matter what way I look at the deer. Some times they are hidden due to the deer position sometimes they are obvious as in a broad side shot. I think it's a great tool to an inexperience hunter as well as the seasoned hunter. Anything that makes the shot seem more real is better IMHO.