Personally I like getting guns in calibers that are common place and easy to find at any store that sells ammo. .380 is fairly common place considering the other choices you listed. It is also less expensive, and most big chain stores will also carry it if you need some ammo and are in a bind. For me, since I already had a Bersa thunder .380, the chocie was obvious.
I like my NAA .380. I just can't part with it. I like all steel guns, and I like being able to carry 18 rounds in tiny little mags completely unobtrusively! If 18 rounds of 380 can't save my hide, I doubt anything else really would! My guardian is an up close and personal gun, a "belly" gun. I wouldn't trust accuracy much past a few yards for me.
To each their own. I like my guardian. It is a damn sexy gun. Only mechanical problems is I HATE disassembly, and after firing all six shots, sometimes the last casing gets caught. Not a big deal....I already sent 6 rounds down range. If I have the time to reload, I have time to clear the side
Great BUG or holdout gun, made of good stuff ( Kahr makes the slides) that will last the years. Screw those plastic kel tec buggers. NAA has great customer service, great mags, great products!
I recommend the common round of 380 in the NAA model. Also, I would go with it ballistic wise. 102 graind golden sabers are nothing to scoff at. Methinks internet ninjas often deride the round unfairly. Do some testing on your own. 1 Test= 1,000,000,000 internet opinions. I watched .380 rounds shred through a steel car door, and do a lot of other impressive things. The round really isn't the slouch everyone claims. America is locked into this bigger-badder-better deal, but .380s were used extensively in other theaters to good effect.
Go online and find where someone shot their attackers a few times with .380s and were found to be insufficient! I bet you wouldn't find much.