I don't own a PK-380, but I have been researching them recently because my wife is interested in one. It has some unique aspects that you should be aware of:
- The slide-mounted manual safety moves in the "wrong" direction compared to others (like the Px4). I haven't tried it yet, but I think this will make it more difficult/slower to disengage the safety under stress.
- The safety does not double as a decocker. This allows "cocked & locked" carry (unlike the Px4), but also means the only way to decock is to pull the trigger and ride the hammer down with your thumb.
- There is no slide lock/release lever. The only way to lock the slide back is to have an empty magazine.
- Disassembly requires a special tool. This is the only gun I know of that does this.
- It only comes with one magazine.
Despite these weird characteristics, the PK-380 is still "in the running" because the ergonomics are good, it's ambidextrous (she's a lefty), it's relatively inexpensive, and she is exactly their target demographic: a female, first-time gun owner. (It does come in pink, after all.) If none of the above bothers you, you'll probably like the PK-380 fine.
The Px4 is a fine firearm, although I was disappointed by it. It looks good, but I think the ergonomics aren't nearly nearly as good as they could/should be.
If you want to OC some times and conceal others, I would recommend a compact (as opposed to a subcompact or full-size/tactical) pistol. They're usually small enough to conceal if you choose, but also suited to open carry. Since both your current contenders are DA/SA, I'll assume you prefer that trigger style. That would rule out Glocks, XDs, M&Ps, Steyr, other Walthers, etc.
If you really want both a DA/SA trigger and the rotary-action lockup that the Px4 has, try to find an STI GP5 for comparison (although finding a holster for it might be even harder than finding the gun itself). Other mid-sized pistols in that size & price range you might want to consider are: Sig P2022, Baby Desert Eagle, EAA Witness compact, EAA EZ (near-clone of a Sig P226), and Bersa Thunder9. There are other offerings by H&K and Sig, but they'd cost twice as much.
Good hunting!
