Both are dependable, accurate, quality firearms. Both are a good choice for carry. Your decision will probably be made depending on HOW you plan to carry, your body size, and mode of dress.
I had a Glock 27, but it was just too thick for a concealed carry gun on me. Lots of guys do, and have no problems, but it just didn't work for me.
I'm over 230lbs., wear blue jeans 99% of the time, and there's not much extra room between me and my Levi's for 1 1/4" of steel.
The Kahr fits better in IWB carry, pocket carry, as well as any where a Glock26 will fit, but it's got a 4 round deficit. There really is very little actual weight difference, but the Kahr feels a bit heavier because it's smaller than the Glock, at almost the same weight.
If you aren't going to carry IWB, or you're a slim guy, or you wear loose waisted pants, and you won't "pocket carry", you may prefer the extra 4 rounds that the G26 has to offer.
Be sure to handle both extensively. I also had a dislike for that hump at the rear bottom of the grip of my G27. It felt like I had a golf ball pressing into the web of my hand.
I finally settled on neither, but went with the Kahr P9 instead... I just don't like pinkie swingers.
But my wife's well protected and quite happy with her MK9.
Just to keep the attacks to a minimum, my next handgun purchase will most likely be a Glock 23 for those days I can get away with a bigger gun.