Mobow, for 2x reasons a larger pin is usually used in the bowhunter freestyle class for spots. First is because you will see less percieved movement, and trust your pin float much more just allowing your self to focus on where you want that arrow to go, instead of where you pin is. Analogy........when driving your car what would happen if you looked at the road directly in front of the hood, instead of100 yards in front of you?You would likely see a lot of choppy, controlled corrections to your steering. It's too tempting to try and overcorrect this way, andforce your aim, instead of just focusing on the spot you want to hit. Make sense? If you have a pin large enough to just cover up most of the yellow, your eye will automatically center things up, it's human nature. It's just sooooo much easier to trust your hold this way.

In addition to this, if you get a big hole in the target that isn't in the middle, your arrow has a tendency to go where you are looking.......sucking you into these holes. If your pin is big enough to cover most of the yellow, you can't see these holes (unless they were really bad [8D]).

I do shoot a lens, but I use a black ring on my lens, it allows me to just stare at the X instead of the movement of my scope.

Now for 3D throw all that out of the window. Completely different game. Now your not able to see a specific dot like on a spots target, your looking for a specific detail, hole in the target, corner of a shadow, etc. Most will also agree that it's much easier to trust your pin float on a 3D target because you can't typically see the X ring and can't see exactly how much your floating on it. Most of the time my aiming point is on a chewed up spot on the target and I've got to see as much detail as possible there to know I'm holding on the right spot. Make sense?