If I did get the DoubleTap, I'd probably load it with the 100 gr Hornady FTX® Critical Defense® Lite. Its more like a 380 ACP than a 9mm.
I'll admit it is more of a novelty gun that I just want for the sake of having it.
The things are getting very cheap now. When they first came out they were a whopping $600 And they're still listed at $599.00 at Gander Mountain, but in reality you can buy them NIB now for $175.00 - cheaper if you really search.
There was some interest in this gun, even in 9mm at first but on the forums I would always counter that the thing was basically the same size and weight of a Rohrbaugh R9 but with a lot less rounds. But that was when those derringers were a lot more expensive.
I thought it made sense in 45 for those people who would never carry anything less than a 45 for self defense - there are still people out there with that mindset. But in 9mm it didn't make sense, at least not at 600 bucks a gun.
But at $175 it kind of tempting