Ever since I've been shooting, I've used a sock with dry rice in it for a rear bag (it's a green army sock that the dryer spared, so it's tactical lol). I've been looking at several commercially made and the DIY thread rear bags. What about them would be better than my field expedient rear bag? I think it works fine, but I'm willing to drop some $ on one if there is a marked difference. Thanks in advance for any input.