I've owned a Kahr K40 (all steel, blued, and .40 S&W, of course) for almost 2 years, and frequently carry it. It has a full-size grip, the curves of which are patterned after the classic Browning HiPower. The magazines hold 6, plus 1 in the chamber.

It's very accurate, carries & conceals well; I like it.

A friend just bought a P40 (polymer frame version of same gun); it's lighter, but other than that, the same. He also had a KelTec .40-cal. He said he didn't like it nearly as well as he did the new Kahr. Also said the KelTec was not as accurate, and recoil was much worse. (Not knocking KelTec--I also carry their P32!)

The only problems I've experienced with the Kahr were in trying to change the sights--I broke the factory front while attempting to drift it out. I saw the error of my ways & had a local gunsmith complete the job for $20.
The other "issue" has been finding a spare mag carrier that fits a single-stack .40 mag. While I know I can order a "custom" one from Kramer, or another holster maker, I'm a cheapskate...er, ah...very frugal...and prefer to shop around.

In other words, no problems experienced with the gun.

HTH YMMV LSMFT,

David