The ppk is an amazingly reliable firearm. Because it's a blowback design, it's very immune to limp wrist failures, in contrast to most semi-automatic pistols that delay ejection until chamber pressures go down. This limits you to .38ACP but the trade-off is increased reliability while maintaining a small package. These firearms can also be miniaturized, for instance, my Bersa Thunder cc fits into my front pocket and is quite a nice EDC (we have constitutional concealed carry in Kansas).