The S&W made PPK and PPK/S have a bigger beaver tail. I personally think it is ugly, also they laser etch the lettering as opposed to rolled or stamped, which looks kind of cheesy, but beauty is in eye of beholder.
The Interarms made in USA Walthers (from years ago) get a lot of bad press, but the one I have seems to function just fine, so maybe they aren't all bad. Additionally, they are made very close to Walther spec in terms of appearance. You can still find them NIB occasionally at websites mentioned by Stainless. I don't doubt the German made Walthers are likely superior, at least a little, but you can't get the German made gun in stainless steel as far as I know.
If you examine a Smith-built Walther along the machined lines of the pistol, you will quickly see that they do not pay enough attention to detail.
Curve radiuses that are not even, machining marks where there shouldn't be any, and the beavertail "improvement" they want to sell the handgun buying public.
This is farther from the original PPK and PPK/S design than even the Interarms product ever was. As a matter of fact, I would rather have an Interarms produced Walther than one manufactured by Smith and Wesson.
Interarms made PPK/S and PPK in blue and stainless and in .32 and .380.
WaltherUSA (S&W) now shows both PPK and PPK/S on their web site in stainless and blue. The PPK isn't available yet, but I understand that the PPK will start rolling off the S&W line around November. I keep hoping S&W will get serious about their Walther project. I'd like to see S&W offer a choice of either their new "improved" beavertail frame or the older classic one. Also like them to offer both guns with light weight alloy frames. And finally, would like them to offer both in .22LR. If they'd do all of this I think they would sell a bunch of pistols, especially if they keep the pistols reliable and keep quality control up.--Leigh