I have not owned a Kahr pistol. I have some experience shooting the Kahr CW9 owned by fellow shooters. Some important differences between the Kahr series, and the CS9, in my observation and experience, are durability/reliability issues with Kahr, and the CS9 has a manual safety.
I have observed Kahr 9mm pistols used as off duty guns by some officers. The complaints were of unreliable feeding till a few hundred rounds had gone through, sporadic jams after that, and shavings in the dustcover from slide, and recoil spring contact. From what I heard, and observed, Kahrs customer service was not as good as S&W's. Several officers wound up paying postage both ways. NONE of those guys are carrying Kahr pistols at this time.
I personally fired some of the offending pistols, and was not impressed with the trigger, felt recoil, or accuracy.
I have shot two CS9's. One blue, and a stainless. Both reminded me of my 3913. They were reliable with various types of ammo, and accurate. Especially accurate for small pistols, IMO.
The CS series does not fit my hand well, or I would own one of each. I went with the 3913.
I would try and shoot both pistols to form an opinion were I you. Good luck! Hope this helps. Regards 18DAI.