I bought a well-used West German made PPK in 1995. I'd always wanted one, and around that time there was an article in (I think) HANDGUNS magazine about a custom job that Krebs Gunsmithing in Illinois was offering (
www.krebscustom.com). Among other things, the gun was "de-horned" and had an extended grip tang welded onto the frame. (I have big hands and long fingers and an extended tang was an absolute requirement for me)
I had such work done on mine the next year. It's very nice. The sights were replaced, the trigger action smoothed up, the tang extended and the gun refinished.
It wasn't cheap, but it sure is neat. I got a stylish shoulder holster from Mitch Rosen to go with it, along with a leather belt holster, and later on a kydex holster from Ky-Tac.
I'm not sure if Krebs still offers that package.(It isn't listed on their website)
However, Cylinder & Slide does (
www.cylinder-slide.com) and they have a link on their website to a review in the May 2003 issue of COMBAT HANDGUNS.
There are better choices to be made for small concealment guns these days, but the PPK is still elegant and appealing. (And it's neat because of the connection with the older James Bond movies. That's why I bought one . . . )
I may have to put a slightly heavier hammer spring in my PPK -- if I shoot European 9 x 17 ammo with hard primers, sometimes I get a failure to fire on the first strike. It's 100% with Federal Hydro-Shock HPs and Silvertips, however . . . .
I have found that both my PPK and Sig 230 are ammo sensitive -- the critical dimension seems to be the overall length of the round being employed. Both guns seem to run better with rounds that have a slightly longer OAL. I've had good luck in both guns with Winchester Silvertips and Federal Hydra-shock, and any generic ball that does not have a stubby round nose bullet.
In January 2010 I bought a .22 cal Walther PPK/S, which I use as a sub-caliber practice gun for both of my .380 pistols. It's a splendid little gun, fun to shoot, and not at all ammo sensitive. I've been shooting that gun on a regular basis to keep my skills up, BUT the tiny issue sights are beginning to be a real challenge for my old eyes if I'm shooting on an indoor range that has spooky lighting.
I don't shoot the PPK all that much BUT I have broken firing pins twice. Apparently this is a common problem. The last time (2012) I had to ship the gun back to Walther to have a new firing pin of a new design installed.