That containment is also that little extra confidence at full draw........just knowing that it's probably going to take a squirrel attack to screw things up is a nice peice of mind. You just don't have to take your eyes off the target. With a prong rest you just can't help yourself but to look down for at least a second to make sure all is well. (If you say no then your lying
Matt, I know what you mean about prong rests, although there are arrow containment doodads you can install for them. Personally, I don't like the idea of keeping a broadhead tipped arrow on my bow at all times. I've always lived by the adage, "Never load your weapon until you're ready to shoot."
Shooting my stickbows off the shelf with rug rests, I can load an arrow on the string by feel, draw and shoot without ever taking my eyes off the game.