I beleive Kahr makes a good product. Their size and shape do fill alot of needs out there. Once you move away from their PM series, they are too over-priced. If I was looking for a mid-sized (not pocket sized) gun - I would not buy a Kahr - I am a Glock guy and own 2 of them with a 3rd coming soon.
I have heard Kahr has has more out of the box issues than most any other polymer handguns and print that they want you to do a free 200 round break-in period - which I have issues with, but that just might be me...
I have had a Kahr MK 40 for about 8 years and I have never had a single problem with it. Well made all metal and small enough to put in our pocket if you don't want to use a holster. It shoots straight and I have never had a misfeed and I didn't have to run a couple of hundred rounds through it before it operated correctly. You can get a cheaper gun but it won't be as well made as my Kahr.
I have a PM9. It's extremely concealable, reliable and accurate. The older models had long hard trigger pulls unless you bought the elite series. The newer ones have the elite triggers and are smooth.
I'm also a Glock fan and see no difference in the performance or reliablity of either firearm.