Does this matter in the selection of a defensive carry pistol? The answer would be no except that such a discomfort may end up reducing the amount of time a shooter spends training. To maintain shooting skill with a given firearm, rounds need to be sent downrange. Sure, I know folks who only shoot the minimum required each year by their state, agency or military service unit. Such folks often make me shake my head. If that's all they can afford then I can almost understand. But I do truly believe that if you're going to carry a weapon for self-defense then you should be on the range at least quarterly and preferably monthly. When you're shooting that much the blister caused by the Kahr (which may not happen to you depending on the size of your hands and your shooting methods) should form a callous pretty quickly. So, overall, does it matter much? Not in my world.
The conclusion that I came to - subjectively - based on my own personal perceptions, needs and skill level, was that I'd rather carry the Kahr CW4543. That said, I wouldn't be at all disappointed if I HAD to carry the Glock. Both are serviceable arms that are capable of putting big holes in bad people at reasonable combat distances... provided you do your part.