I too had a few Glocks, G17, G19, G20 and G21. I liked most everything about them but the grip angle and fatness.
The G20 I actually kept and carried a lot for nearly 10 years.
I had forgot about Glocks for a while but last year I got a G48.
Man, what an improvement to me, better angle grip wise.
It is way thinner than a G19 and lightweight too, and with the SA metal mags, still holds 15 +1.
The Ameriglo Tritium red ring front sight is fantastic too.
My G48 in the middle, and my friend's G19 and I think the other one is a G43.
Shooting the G48 alongside the G19, the G48 feels much better to me.
I am also a lefty and like that I could change the mag release over, and the Slimline (Glock's terminology, not mine) keeps it, well, slim.
Overall width at top of grip is 1.1 inches , but the slide width is only .87 inches.
Magazine on the left is a Shield Arms with +2 extension, so a 17 round.
The G48 and my Hellcat and my two favorites now.
I'm not sure if Glock's Slimline series will include other calibers.
It does mean reduced capacity, the G48 factory polymer mags only hold 10 rounds of 9mm, but Shield Arms stepped up with a good steel mag that gets 5 more rounds in that space.