Here's something you don't see everyday http://www.thefirearmblog.com/blog/2013/01/29/never-empty-double-gun-nedg-carbine-stock-for-two-pistols/
Never Ending Double Gun - "When one gun runs out of bullets, just that gun can be selectively reloaded, while the other gun is maintained in the ‘ready’ condition, which ensures that the operator is always able to fire the unit ‘immediately and without hesitation.'"
I can't see someone swapping mags smoothly or quickly with this thing. Anyone else think this would be a easy swapper?
Maybe not. I think a person if being right handed would end up just using the firing hand pistol the front one would act as a back-up. Other than that it would get confusing. I can see all sorts of thing going wrong trying to use this gun in a real life setting.
Like other weapons, it'll take a bit of getting used to. Meaning practice, of course. That said, I can see an interruption in firing while a mag is changed regardless. What it does do is provide twice the number of shots over one pistol. Whether that offsets carrying a carbine with a 30 round mag is a whole 'nuther question aside the potential for failure of one.
I see only one real advantage. In case of a jammed shell, you are still active, and effective. Personally, I think it stinks. Two separate pistols would be much more concealable, could cover two directions at once, and more versatile.
I don't really see enough use to justify it as a serious tool. That said, I could see me buying one and throwing it in the range bag for fun...