The Kel-Tec PF9 has been my everyday carry gun for some time now. It's solid yet unpretentious, and it has the cardinal attribute of all good carry guns--it goes "BANG!" every time I shoot it. It's inexpensive, enough so that you can afford two or three for the price of some its pricier (although quite nice) competition.
It's drawback, like every other small 9mm pistol, is that it is unpleasant to shoot if you shoot more than 50-75 rounds at a time. All of these guns are really meant to be "carried a lot and shot a little".
Apparently some Kel-Tec engineers decided to remedy that by producing a .22 conversion kit for the PF9. My sole issue, being the cheap-ass I can be at times, is that the kit is $200, and an extra mag takes it to $235. Given that this is roughly what I can buy a PF9 for, I'm really having a hard time justifying the purchase--especially since I've bought a lot of gunnie stuff in the past couple of months.
So help a brother out--give me some good rationalizations I can use on myself. :-)