I have owned 2 kahrs .both were 9mm, the PM and the TP series. They were both fine firearms. The TP series was a joy to shoot, The PM series was not as fun but still manageable.
Negatives on Kahr. Even being a very small firearm, it is very thick. It does not have second strike ability on a miss-fired round. It has a shape that recoils in a flip of the muzzle. (i prefer a torque recoil). And the deal breaker that made me sell both Kahrs was the magazine and mag release button. The magazine has a low cut in the forward section for bullet feeding which allows for spare magazines to shed a bullet or 2 in my pockets. A few times the magazine release would press wrong when concealed and partially release while holstered. The finial straw is the ugliest handgun ever made goes to the GLOCK, i considered a kahr a shrunk glock .
The R9, It has very pleasing style lines, Fits the hand very well, and is very thin. It will slide in and out of a pocket with out snagging anything. Has second strike ability, The mag release is not in a place to be accidentally engaged. With the light weight it will not sag and print like other firearms.
The negatives, Ammo sensitive, but i am willing to feed it what it likes. Cost is high, we pay a dear price for our Pup but in my opinion it is worth the $.
Shoot ability, I like the smooth trigger pull much better on
the R9. A good trigger is a thing of beauty. Recoil is subjective, But it takes practice to tame the torque recoil.
Maintenance and changing out springs, on the R9 you have to understand that the springs need changing at regular times as well as lube. This is not a bad thing either because i believe with to many guns we let this go until it stops functioning.
The last Item of concern is no +P or +P+ ammo. very good defensive ammo exists for regular pressure 9mm. When i carried a SC 342. it was carried with a 38 special load because the magnum loads were unmanageable.
This is all just my opinion, The short comings of the Kahr i could not over come, The short comings of the R9 are well worth the trade offs.
Frederick