I was looking for a Glock 23 gen4 but could only find the 17, 19, and 22 gen 4s. I think we don't hear much about them casue we can't find them. The only issue with the 19 gen4 is the recoil spring with some ammo; since the 23 should have the same recoil spring it should not have any issue with FTE due to the heavier caliber. You can also get a 9mm conversion barrel and shoot cheaper ammo for practice. Reliability is great, trigger pull is th same as any other Glock. If you reload be carefull about inspecting the casings. Recoil is heavier than 9mm but nothing worse than any other light and small 40 S&W. I may get one if I find it!