TR: It could be that I just shoot Glocks better. I'm one of those who likes the factory sights and I go so far as replacing them with the steel version after I damage the plastic ones from holster-ing and un-holstering and otherwise dinging the heck out of them and I do.
I have also become very accoustomed to the trigger reset and the Gen 3 23 and Gen 4 22 frame sans any backstrap sleeve fit my hands perfectly. The slide is relatively thin although it appears blocky so it carries well. I AIWB a Gen 3 Glock 23 all the time so they are second nature to me.
So, you could be right, it's me and the gun versus the type of barrel rifling. Whatever it is, it just works for me. I've been Glocking since 1993. I hated them until I got used to the whole idea. Now I would not own anything else. They do take some time to warm up to. They did for me anyway.
ALL: I am hearing the 19M will not have the IMO silly mag well flare and if this is the case, I will buy one when the price and time is right.