The Kahr might be a bit more intimidating than your baby Glock. BTW, is the Glock a 9mm?
I don't think I would give intimidation value prime consideration in choice of a handgun. I think you should think first and foremost about what is going to best do the job if you do have to use it. What is going to be good enough to do the job; what can you shoot accurately and well; what will be practical for you to carry.
Unless you're dealing with something really small, I'm not sure you would get that much higher of a back-down rate based on the size of the gun.
There's another important factor here in the back-down rate: your demeanor, and I'm not sure you can convincingly fake that in the stress of a real confrontation.
Personally, I wouldn't count on simply sticking out a big, "intimidating" gun and counting on that to do the trick. Sounds better to me to have a mid-sized gun and be prepared to use it, than to have a big one and not be prepared to use it.
My demeanor is along the lines of "make my day" (I brandished once to a stalker trying to break into my glass door at home) I thought at the time he was mortified at the sight of my big, shiny Magnum as his eyes were fixated on it.
I just can't say I would have gotten the same 'scared rabbit' response with my carry Glock.