How do you get any of this out of your back pack, without taking your gun off your shoulder, finding a place to lean your gun, removing back pack and digging through it? Been there, done it, found it to be inconvenient, noisy, cumbersome....The LBV puts everything in a separate pocket right in front of you for easy access. I'm getting one.
Oh, like rattlin horns and stuff? Seems practical.
Cleric, check out Hill People Gear. Quality product.
Sure, and any of the other myriad of things people take with them hunting...
Binos or spotting scope
First Aid kit
Pretty much anything you might want to put in a backpack when you go hunting.