If you enjoy the forum please consider supporting it by signing up for a NES Membership The benefits pay for the membership many times over.
EMP 9MM gets a writeup and review in this month's American Rifleman.
The only reliable Walther I've shot was a P-38. The PPK/S and the P22 which my dad own are both shit.
I have a German PPK/S made in 1971 and it never gave me any problems at all. I've fired 1-2K of reloads (RNL and JHPs) and carried it for many years.
The P22 I don't want to discuss . . . do a deep-dive Search here for my story on that gun, including the alleged fix that made it reliable finally (for the next owner).
I carry a P99 .40 frequently and again, it's been 100% reliable with everything I've fed it.