The 19x has many features that a 19 with a 17 mag in it does not have. Setting most of those aside, and just focusing on the grip configuration, the 19x has an interesting new integral feature that even a 17 grip doesn't have, and which is "the opposite" of the 17.5 grip. This feature is the front grip strap' slight extension straight downward, not only eliminating the cutout found there on the black 17.5, but actually shielding the gap, thereby reducing the chance of pinching the outer edge of your hand/pinky when a magazine is quickly inserted. Though not as painful as 1911 "hammerbite", this glock "magpinch"--which can occur for some people when a flush-fitting mag is slammed in quickly--is distracting if your hand's grip position makes you prone to it. The front gripstrap's downward extension on the 19x should significantly reduce or eliminate the chance of that "magpinch".