Kahr customer service treated me well when I needed them. I had some trouble with my K40's main spring when I first got it a couple years back. Kahr sent me a new spring via express mail, but it failed, too. So they sent me another main spring and a new guide rod. I am pretty sure they must have gotten a bad run of springs, but I have never had another hiccup.
But I guess I am one of those "Kahr Lovers." Two weeks ago, I shot TDI's Handgun II & III with my 14 year old Kahr E9. Since it is a carbon steel gun, it's finish has suffered over the years but it was a Singer sewing machine on the line. I got lot's of practice with mag changes, too!