I have owned eleven Kahr's and currently still own five. Four out of the eleven had problems ranging from failure of the slide to stay open after the last round to premature slide lock with rounds still left in the magazine. Never had a failure to fire, however. The ones I currently own have been excellent with four of the five being steel framed guns. The one poly is a "newer" model (2005) PM9 which has been excellent.
The four that had problems were an early version of the PM9, a P40 Covert, an MK40 Elite, and a PM40. I think all of these were fixable, though I did send the MK40 Elite back to Kahr and they didn't correct its problem. Of these, I would have liked to have kept and fixed the PM40. That little baby was a powerful package.
Kahr's have very tight tolerances so the break in period is important. They can also be a little finicky with some ammunition. My K40 Elite '98 will shoot Federal HST loads but when unloading that round, it is a tight fit and can hang up. But that gun has been 100% reliable. Kahr's shine for those who want a little deeper concealable sidearm because they are slim and rather small, their 'T' series being the exception. And they make wonderful guns for women because of their grip shape and size. The K9 9mm is an almost ideal gun for women.