I'm not a 9mm fan in general, but I will concede that with good ammo it's certainly just as good as a .38+p, and a Kahr is easier to conceal. I'm normally a .45ACP and .357 fanboy, but in a concealable gun a 9mm, .380, or .38+p is as much as most folks (myself included) can actually shoot and hit anything, I think anything smaller is a big step down, I'm still trying to figure out the ballistics on the Beretta advertising that their .32 has the power of a .380

My .357s often have the power of .38special, when they're loaded with .38specials
I prefer/recommend revolvers for reliability/more forgiving of neglect, limpwristing etc. Let's face it most civilians do not properly maintain their semi-autos, I don't myself, typically only lube them the day before going to the range, and that's probably better than most folks do. I realize of course that on this forum it's likely that many of you DO actually properly maintain your pistols, I'm referring more the people/gun owners in general, and if I were going to use a pistol instead of a revolver I'd properly maintain mine.