I found this on Defense Review, and I really want one, conditionally.
While I've never been as big a fan of shotguns as most firearm enthusiasts, even I think they're the best thing for home defense. Far more power than a pistol, without the over penetration worries of a rifle (assuming you use buck, which you should).
The Model 1216 is an attempt to solve two of the biggest complaints about shotguns. First, the limited magazine capacity and, secondly, the time consuming reloading process. This thing has four mag tubes, as opposed to one, and the whole works can be detached so you can quickly swap in another loaded assembly.
I'd be bound and determined to buy one if it weren't for one little concern. The mag tubes have to be manually rotated. So, you can fire however many round you have in a given tube, then rotate a fresh one in to resume fire. I see a little problem with that.
Ever seen a movie where, in the midst of the dramatic fight scene, someone goes to take a shot that would certainly kill a more important character, and instead the weapon goes 'click'? I've been that guy. Granted, hearing a 'click' on an empty tube with this shotgun wouldn't be as bad as with a pump gun. Just rotate the next tube and go to work, as opposed to having to load the tube one shell at a time (or combat load while fighting, which is way worse).
I'd have to take one to the range and try a few things out and see how they worked. I think I'd try rotating after each shot, train the muscles to rotate the tubes as soon as you feel the recoil. In any event, even if I decide I liked it and bought one, it'd be one of those guns you have to completely retrain yourself to use effectively.