Yesterday, I received my new Fort Smith dark matte finished PPK/s in .22 LR.  Buds Guns had these pistols on special for $225.  I took it out to the range today, and put a variety of ammo through it.
There were 3 failures in 300 rounds fired.
1.  After lubing the gun with Slip 2000, I fired 50 rounds of CCI Mini Mag HP.  There were no failures.
2. I then fired 50 rounds of Remingtons Viper load.  No failures.
3. 50 rounds of Remington Yellow Bullet.  No failures.
4. 50 rounds of Federal's load for semi-auto firearms.  There was one failure to eject and one failure to feed.
5. 50 rounds of CCI Standard velocity load had one failure to feed.  
6.  I ended with 50 more rounds of CCI MiniMag HP.  No failures.

The double action pull is atrocious. Single action is fine.  I plan on buying more CCI Mini Mags and Remington Vipers.
This is a fun little pistol.

I use to win .25 cent bets betting I could shoot more empty shotgun shells off the 50 foot back stop with my PPK/s .22 then other people could with 6 inch Ruger, High Standard, and S&W .22 autos.

The secret is to know the gun and concentrate on the fundamentals.  The other guys figured they could win easily and failed to pay attention.
The little Walther's are much more accurate then most people think they can be.

The heavy DA trigger is because of the limited room in the small frame design, there just wasn't enough room to increase the leverage, so the DA trigger is heavy.
Installing a lighter main spring very often causes reliability problems, and if you just practice you get used to the trigger and no longer notice it.

I just got one of these but haven't picked it up yet (next week).

Am I the only one who is having a hard time finding mags for these guns? I found the suppressor adapter no problem, but all mags are "sold out".  

This.

I found ONE mag at the gunshot today.