Personal choice, but I prioritize deep concealment and comfort over extra rounds and better stopping power. So, for me, I don't think the extra 4 rounds are worth the double stack bulk and the extra weight of the Glock 26. (If you find yourself in a situation needing the extra 4 rounds of the 26, then you will probably end up wishing you had the 15 rounds of a Glock 19.)
Also, you will carry more often the easier it is to do so, and carrying something is better than carrying nothing. I actually rarely carry my 19. I know other people carry .45's inside the waistband all the time, but I hate that with my 19. To make it comfortable, I have a 5.11 Holster Shirt (see picture of me below)...no one can tell you are carrying (it is an undershirt, obviously)...but it doesn't allow a very quick draw. It makes drawing a last resort...which it should be anyway.
I think if I had a 43, I might carry more. As it is, I rarely do so.