JMOfartO:
I don't have a PPK, S&W or Interarms... I'm an old fart and for decades I've heard the German PPK's are prone to offer the user bad slide "bite", DA trigger pull was terrible, and reliability was iffy.
Never been a "prettier" pistol made in my opinion than the PPK, but beauty is only skin deep and the negative's I'd "heard" about just turned me off so I never bought one.
Additionally, the size and weight of the PPK is such that a person seeking a cc self defense firearm has other choices, in larger calibers.
But for those folks who WANT a PPK and the choices are a used (or even new) Interarms all German made Walther, or a new S&W PPK and asked my opinion I'd say buy the new S&W PPK in a heartbeat.
Why?
Lifetime Warranty.... What's the warranty gonna' be on the Interarms?
I've had dealings with S&W Customer Service and found them exceptional. I had a new PPS last year (that was a pos), and S&W finally gave me a NIB replacement when it couldn't be fixed. (And I quickly sold it).
I'm not knocking Walthers as I love most of their pistols.. In the past I've owned a PP/PPS/P1/P5/P99c/AS and P99/AS.. With the sole exception of the PPS all were fine pistols.
Should you get a "bad" S&W PPK I assure you S&W WILL make it right, or give you another, or whatever it takes to make you a happy S&W Customer.
Not sure you'd get that with the Interarms version.
I'm not knocking the 380cal. for self defense either. My daily cc choice is my LWS380.
Just personal opinion, no offense to those with contrary opinions.
Best Wishes,
Jesse