Between the two, only .380 is a serious contender.
Keeping in mind that you said pocket pistol, you need to ask some questions:
1) Do you feel comfortable with a loaded semi-auto in your pocket and a short, fairly light trigger pull like that on a Glock 42? Remember that unplanned things might go in a pocket and get inside the trigger guard.
2) Do you want to trust the safety on a cocked-and-locked Kimber or Sig pocket single action?
3) Do you mind the heavy trigger pull of a DAO like a Ruger LCP or S&W Bodyguard 380?
I own or have owned all those guns (except the Kimber), along with some pocket 9mms such as the Glock 43 and Sig P290RS.
Because of MY answers to the 3 questions, I only carry the Bodyguard in my pocket. I’ll carry the G43 in a hard IWB and the P290 in a soft IWB.
I’m not attacking the others, so people don’t need to flame me for being cautious and pragmatic.
It’s not really about caliber. Its about what you will comfortably and confidently carry because a 380 in the pocket beats a 45 ACP that you left at home every time!
Boy, it's a crowded market these days! If I could just win the lottery...