I just picked up a Glock 17 Gen 4 today, and noticed something different, compared to my Glock 26 Gen 4. It has a smooth faced trigger, my G26 has grooves in the trigger. My question is, does Glock vary what trigger goes in what model/size of pistol? I picked up both NIB, and have left both of them stock (except night sights on the 26). Not a big deal, just curious. Also, is there any difference between the two triggers, other than the grooves?