I have three 3rd gen Glocks (19, 26, and 20) and love them. If the grip angle and size works for you, I say get the 19. I actually like the finger grooves, but I don't have really big hands. For ccw, the 19 is almost as concealable as the 26 and feels a lot better in the hand to me. I carry the 26 more because it does provide a little more concealment, and I carry around people who may call me out if the spot it. With good hollowpoints, I don't feel undergunned at all.
I have never shot a 23, but it's the same size as the 19 and should feel and conceal the same. I can't afford to feed too many calibers and like the interchangeability between my two primaries (the 26 and 19). Therefore, I wouldn't rule out the 23 if you already have a couple of .40 caliber guns and don't want to start stocking up on another caliber.