Gen 5 Saves on production costs for round holes and pins.You should be aware that the Gen5 models ALL have a modified SLIDE and FIRING PIN that use the conventional round FIRING PIN tip.
Almost everyone else has used the round point for the last 140 years. Mechanically it's stronger than the flat Glock FIRING PIN point.
I have a Gen3 G35 that started to have failures to fire. Good indent on primers. I blamed it on my reloads having high primers as most would fire on second attempt. Not the problem. Replaced firing pin spring. Nope. After several thousand more rounds with the failures happening almost every mag I was at and end.
Removed all internals and sent the pistol to Glock for refurbish with letter explaining my problems. Received the Glock and went to the range. Not a single failure in several hundred rounds.
I got to thinking that maybe Glock had fixed a problem with the gun. Removed all the new parts and reinstalled the old. The problem returned. This Glock had been fired about 35,000 rds. with most being reloads with CCI primers. And yes I tried different primers before sending it to Glock.
Detailed stripped and started comparing the old with the new. Fortunately I started with the firing pin. It was only then that I could see the very fine point on the firing pin was rounded. Primer strikes had looked good but comparing those with the rounds fired with new rounds with a 10X jewelers lupe you could see that there was a definite deeper, sharper imprint. So Glock firing pins can wear out. A round firing pin should be even more robust.
I have not wanted a Gen 5 but when they make G27 in black I will have one.