Quite apart from the recoil, I can't imagine why anyone would want a six-inch, heavy gun holding only two rounds and with a lousy trigger,
Where I'm sure the size, weight, and trigger aren't an issue, the two shot limitation along with the $500-$800 price tag may be what has kept the Double Tap modern Derringer on the ground for a couple years. The last they said they will be shipping in the first quarter of 2013. Now in the second quarter, and I haven't seen any yet. Not that I am intending on buying one.