I own and carry a SW MP 340 with lazer and the Kahr PM .40 SW. They are both fine weapons achieving their respective design purposes. You are right there are many such threads "this vs that." I have sifted through the opinions, pros and cons and look at me, I wound up with both of them. Now the real truth is I have several other concealed carry pieces that I carry as well in rotation because first I can, second I own them and third carrying some of the others brings me certain levels of pleasure... like a fine watch or set of golf clubs may give someone else a lift.
In the end you must decide what your "design purpose" is and then choose the gun(s) that fit your goals to your satisfaction.. it matters not what another opines if "it doesn't work for you".
I can tell you that both guns are very well made, both are very light weight, small and easily concealed in a variety of ways. IWB, OWB, Thunderwear, pockets etc. I tend to return to the lighter weight guns and then choose the one that works with my required attire for the day. And yes sometimes I change to the other carry piece just for a change.
Is the possibility of a lazer important to you?, Is the ease of a quick reload important to you? Is the simplicity and dependability of a revolver more important to you than quick reloads? How about the ability to shoot multiple calibers? Have you been able to shoot either of the guns you mentioned? The snubbies with fullhouse loads can be a handle, some would even say painful. The Kahr nines will be more gently on your hands but with the narrow grip may be difficult for people with longer fingers.
So you see it is not that there is only one correct answer for everyone. Let me encourage you not to buy as though it will be your last gun purchase. Your needs may change and you taste may change with experience and luckily guns tend to hold their value. To make it easier in the future to change guns just remember to "buy right". If you don't buy impulsively and pay more than you need to for a given gun, you will be able to sell it for less than your competition later.
I hope this helps you in your search for your holy grail.