Adjustable Shotgun Stock

I saw that Remington was selling "tactical" versions of their 870 shotguns with these stocks and they look like a great add-on for any shotgun! Knoxx makes some huge claims about how much felt recoil reduction you'll get, but aside from all the numbers, they have some wicked videos showing folks firing the shotgun with someone's should sandwiched between a wall and the stock and even someone firing the shotgun while it was pressed against his belly! I'm a pretty light guy, so something like this really appeals to me.