Some S&W ppk/s manufactured in 2009 2010 just after the recall, has poor to very bad tolerance control.

I bought a NIB PPK/S-1 picked it up in Jan 2010. Unfortunately it never could make it through more than one magazine without freezing up or jamming. By freezing up I mean in firing the action would freeze up rock solid in the firing cycle. Need to disassemble the hammer block .
Sent it back under warranty four times for repair. Fifth time for full refund by S&W.
Yet most S&W ppk ppk/s were very good .

If purchasing a new ppk I would consider a ppk instead of the ppk/s (prefere the shorter grip) and get it by Davidson's in case I got a lemmon.

I am certainly not a Walther snob. The PPK design is finicky. I would buy a S&W ppk or PPK/ S but inspect it. Areas over looked are the extractor and the engagement (how well does the trigger bar fit) of the trigger bar
Also pay attention to ease smoothness of the hammer block plunger. Make due no signs of bubba Dremel polishing of ramp and rails.

I have used Davidson's for a Ruger lcp because it is easier to deal with a one time swap out of such a type of pistol rather than going back and forth to the manufacturer. But that was about 10 years ago.