For me, the choices come down to exactly two: the Walther PPS and the Kahr PM9. They both are roughly the size of a Walther PPK, but are full-power 9mms that weigh 20 ounces or less.
Personally, I didn't like the feel of the PPS, so I bought a Kahr PM9. Then, to put the icing on the cake, I bought my PM9 directly from Cylinder & Slide gunsmiths, where they performed an additional $500 worth of magic. Why did I spend that much extra money on an already-expensive firearm? 1) As Clint Smith says: "Because you can"; and 2) my ass is worth the extra investment in my primary CCW weapon.
This Kahr PM9 is a wonder. It weighs only about 16 ounces dry, yet it will hold 6 + 1 rounds of +P 9mms (7 + 1 with the included extended magazine). Cylinder & Slide did a trigger job, polished about everything possible, and added XS Tritium sights. XS sights are not designed for precision work: they're designed for rapid target acquisition, day or night. And they work. The trigger is like a very well-tuned S&W revolver. This little beast has been 100% reliable since the first round fired. The ergos are great; it's surprisingly controllable despite the light weight.
IMO, in this age of light weight and great metallurgy, there's no reason to carry a CCW piece that weighs more than 20 ounces. I absolutely love my SIG P239s, but they're bricks compared to the Kahr.
