The purpose behind the 'Gap' was to be able to put the .45 in a 9mm sized semi-automatic. As Glock does it, there is no advantage to it as the grip is large anyway. It could be of use to people with small hands if a 'downsized' 1911 were made. I have seen a couple of prototypes, but I don't know if any are in production. As to the 9mm against the .45, that horse has pretty well been beaten to death. Yes, a 9mm is good with the right bullets, but with the same bullets, the .45 is still better. The .40 S&W is again, an attempt to get .45 power in a 9mm sized handgun. You have a cartridge loaded to much higher pressures, and a lot more 'buck and roar' to get the same ballistics as the .45. And now it is being down loaded with 165 gr bullets rather than the original 180's to make it more comfortable to shoot (and loosing the .45 ballistics in the process). Enough said, just go get yourself a nice .45, you will love it! 44 Man